Do you have a room which has good daylight and a cooler temperature than the rest of the house, for instance 45/50f? If so, (you don't say whether they are growing in the garden or in pots), if growing in the garden, cut them back to about 10 inches, you have to leave the stems a bit longer than the normal hybrids/cultivars, and pot them up.
If in pots, cut them back to same height. Let them dry out a bit before doing this, it cuts back on sap loss of the cut stems. You can if you wish re-pot them at this point into smaller pots, by removing the bottom third of soil and roots, then they will take up less room indoors. Keep them just moist, never overwater, especially during the winter time. If it is possible for you too overwinter them this way, they will start shooting again after a couple of weeks.

As they are species varieites that you have, you can't really overwinter them in just a frost-free place with no light, it would be too cold for them.

When you say you are having no luck with f.procumbens seed, are you using fresh seed straight from a seed pod/fruit? are you planting them too deep? just lay seeds on top of the soil and only just cover with a very small amount of vermiculite. Don't keep them too wet.

If you've had no success with cuttings planted in soil, are you leaving the stems too long?, you only need a 'tip' size cutting eg max. length 1 inch or less. Are you keeping them out of direct sunlight? Are you keeping them too wet? Have you tried rooting them in water?

Hope this helps you - Kath:)