Geographical location?

Note that the three kinds you mentioned are all quite slow-growing (except for largest and most robust kinds of rhododendrons) and generally produce their best appearance on moist, well-drained soil in partial shade. Even where soil conditions support good growth with tolerable foliage appearance of hybrid rhododendrons (such as in grower's fields in Oregon) the flowers will not hold up as well during any warm, sunny days that may occur during the blooming period. This becomes more of a factor the farther along in the year it is.

Pacific wax myrtle and Italian buckthorn appear to be pretty good ones for this area, although if you are towards the mountains the buckthorn will probably freeze at some point. Burkwood osmanthus seems to be pretty durable, it grows rather fast when watered. Hollyleaf osmanthus was one of few repeatedly seen broad-leaved evergreens pretty much not burned at all by the cold in 1990 (other than rhododendrons, azaleas, pieris and box!).

All of the these last will probably need some containment at some point to remain as short as you have stated you want. But the first two will poke up more quickly than most or all of what you have gotten together so far. That's almost always how it works, the quick hedges get big and the more restrained ones take forever to develop.

The classic hedges are yew, holly and box. Like box, yew may discolor disturbingly if conditions aren't just right. Holly (English holly, in this context) has become quite a weed in this region, planting much of that is not a good idea anymore. Japanese holly is another small-leaved, slow and low (until a long time has passed) thing like box.

Thanks for the plant suggestions; I am in Zone 7 I believe, Centralia area. Only eight feet tall is not a requirement; I just don't want to end up with anything 60 feet tall.
Cost is another main concern with the amount of shrubs I would like to plant this fall thus the gallon containiers. I understand it may be 5-10 years before there is much of a barrier and thats ok as long as they are there and growing!
I like the form of the rhodys and pieris so wondering what to add for interest, design, etc. Since it is going to be a straight line of plants would it look better to stager the height with taller plants?
Thanks again,
Eva

Plant small groupings of several specimens of each kind close together in the same section, with the relative heights dispersed in whatever manner seems pleasing. 4 pieris then 4 rhododendrons and so on. If a thick border is possible or seems desirable you can plant a strip of the shorter-growing ones on your side with the taller growing ones in the back half.

Evergreen huckleberry looks well with rhododendrons. Camellias are nice with pieris. Tall Oregon grape is a good blender, going well with many other evergreen shrubs. However, there is quite a bit of rust on this at the moment, perhaps due to recent spring conditions. How much varies with the individual, but one some it is quite noticeable.

Thank you; so plan the fence line simular to how I would do a bed by grouping them in small sections. This gives me direction:-)

You'll save money by learning how to propagate the shrubs yourself from what you've already purchased.

An event called Green Elephant has regular free plant swaps at a parking lot in Redmond, WA. In January there is a hardwood cuttings workshop and even a beginner like me got some things to root. That might be a great place to start.

Swaps are posted on the Pacific Northwest Garden Exchange forum.

This has been helpful to me. I didn't think about the planting them in groupings which helps me solve the problem of some sections having some shade from big trees while other sections are in full sun.

I wonder what you suggest if you want something a little faster growing? I am good with plants that top out between 8-20 feet. I think that pyrmadalis looks too formal for my country home - this is to give privacy from the neighbors along a shared fenceline.

See my first reply.

Also there are some species of Fargesia bamboo on the garden center market here these days that are pretty enjoyable, being fast, dense and graceful. Hardy clumpers that spread via short, close rootstocks, like irises, and never send out long runners.

Thanks everyone for all of your help! I like the idea of the Fargesia bamboo (sounds like a much faster grower than the Fire Mountain Pieris I purchased). On each end I plan to add a triange of three Pacific Wax Myrtle and one off center along the fence as I do have pleanty of space to work with.
Thanks to you, instead of being overwhelmed I am getting excited about my fence line planting!!

Eva, I got some super advice from our local nursery when I had an overwhelming-sized problem. Break the length of the hedge down into say 12 foot sections. Choose the plants for one 12 foot section, then repeat. I did this alongside a long walkway this past spring and I'm delighted with the result.

Thanks again to everyone! With all your help and direction my fence line planting will now consist of Pacific Wax Myrtle, Bamboo Fargesia Scabrina, Mexican Orange Aztec Pearl and Rhododendron Roseum Elegans. I am so excited to get started; think I will stagger the rhodys and mexican orange plants more towards the front of my line as it sounds like the bamboo will be a hedge all its own in time :-)

You may see significant cold damage to the Choisya at some point.

Thanks for letting me know; so much to learn. I saw a large Choisya in a local display garden but it was probably protected by the large tree canopy. Since I have already purchased them think I will try to baby them through...in time hope the other shrubs can provide protection and in the meantime you will notice my fence line by the sheets covering them in the coldest weather. Or is there something that will work better for protection?
Appreciate your help,
Eva

What often happens with a plant like this that is in or close to its lowest zone tolerance in this region is that a planting is fine for years - until one day it gets below the minimum temperature for the plant - and then the planting is not so fine. Particularly for a screen I would stick with fully hardy choices myself. But if you want to bother covering yours when it seems killing temperatures may be possible anything that blocks out sun and wind is suitable - burlap on sticks, wire tubes stuffed with leaves and so on. Probably best to keep material that comes in the form of flat sheets off the foliage, so that it doesn't freeze to it. I am sure various methods will be shown and described on the internet, as they are in gardening books.

Now I understand why I dont see Choisya in yards; thought the shrub would be perfect; beautiful, evergreen and fragrant! If I decide to keep it promise I will do better than using sheets :-)

Thanks again for all your help.

I think you need some conifers in there somewhere. There are some really nice golden and blue foliaged dwarf conifirs as well as green ones. To break up all those leaves.
Chamaecyparis pisifera aka Boulevard Cypress doesn't get too tall and is a gorgeous blue with soft foliage. Thuja occidentalis 'Rheingold'is a smaller yellow arborvitae.

Old-enough plantings in the area have 'Boulevard' over 30' tall. And yes, they're 'Boulevard' and not 'Squarrosa' etc.

Thank you for all your help and ideas! The Pacific Wax Myrtle is in the ground and now marking for additional plantings.