this site has good information about growth habits, flowering period and other details for many cultivars of camellias. i am fond of pinks and whites but your color preferences may differ.
my oldest camellia is probably 7' wide/10' tall after 25 years of growth so perhaps you could consider that as a reference for plant spacing.
'pink snow' has been the fastest upward-growing of my plants.

Here is a link that might be useful: wintergarden camellias

Thanks Jeff. I enjoyed the wintergarden site. They do include several full bush pictures, which helps a lot.

I would need something fairly fast growing for the area in question, and also something that wouldn't mind some pruning for size someday in the future, if need be, although I have no wish to hack away at them. What would your suggestions be for that? I like pinks and whites (probably my favorites) together, but I also like the reds too. I think they're all beautiful!

I have a small Leslie Ann in a pot that I haven't planted so far, but am not sure she would be suitable in a hedge. I also have several unplanted Japonicas.

I have heard of Sparkling Burgundy being used as hedge, but have heard she has a more weeping type of growth habit. I want to vary the look with a few different colors. I have heard Pink Snow is lovely, and the wintergarden site said it makes a good screen. Are there any combinations you would suggest?

A local garden center has a hybrid called Crimson Candles that is fairly good size. The problem is I have heard many hybrids have a less than desireable growth habit and can look scraggly.

Sandy

i don't think any camellia can be considered as "fast growing" in the typical sense as with other shrubs. it will be several years before you get a dense, tall visual barrier if you plant-space for future growth.
also, i have never used them as a hedge so don't really have any suggestions for that.
if you have room (width of bed), i would stagger them based on line-of-sight toward the most effective screening angle and interplant with some other shrubs that will more quickly fill in the voids.
in your warm zone, the variegated pittosporum tobira might be something to consider. mine has grown fairly quickly into a tall, wide shrub situated in partial shade. the variegated foliage appears as a light sage green color from a distance and would combine well with pinks and whites. fragrant blossoms in spring are a bonus.
if you like formal double camellia blooms, 'white-by-the-gate' and 'rose dawn' have been a couple of the fastest growers for me.

I've had several camellias reach pretty good size within two to three years, so what I think I may do is contact Erinon Camellia farm and pick their brains a bit. I found an internet video in which they describe several varieties of camellias and how quickly (or not) that they grow, as well as sun or shade preferences.

My screen material offers some degree of privacy, much like a sheer curtain, but is see through at night, as a sheer curtain would be. Therefore, I need enough plant material to block most of the view in, but it doesn't have to be super dense to do the job. I think a mixture of bushes that look nice together, and perhaps are barely touching in time would be very pretty, and not commonly seen.

I've even thought of installing inexpensive plastic white lattice if need be until the plants fill in, or using some tall growing perenials. I really want to get away from using common shrubs that everyone else has in their yards.
Maybe I should be treating this situation similar to a foundation type planting, rather than thinking "hedge".

That's where I was hoping someone that has grown camellias in a border type situation, whose principles could be applied in my situation, would chime in. I'm sure there are many camellias whose growth habits enhance one another, and are denser in growth habit (rather than open and weeping), that would work great and would be compatible. I'm just not experienced enough in all the varieties to know who would look good with what.

Sandy

Maybe while they are getting established, you could put some shade netting over them in the sunniest months so they grow faster and don't risk getting sunburned.