I'm sure others will chime in with more advise, but I'll see if I can get it started. Episcias will grow in the same conditions as do AVs, and some people I've seen grow them at the sides of their light stands even. Most the experts, tho', say they prefer brighter light and/or longer days than your AVs do. So far as I know there are no really orange flowered episcias, tho' some come really close--more of a red-orange, or red, or yellow, or pink. A lot of people grow them for the foliage and don't care if they bloom, and with some, like 'Cleopatra' for example, the bloom (orange/red) clashes with the pink/white/green foliage, and the only reason to look for blooms in my opinion is that they're an indication of good health. As far as size goes, some are pretty small, like 'Silver Skies' for instance, and most can get quite large if you let the stolens grow, especially if you pin them down on a large shallow pot or in a moss basket. Even a larger grower can be more manageable and quite lovely if all the stolens are pinched off. The leaves get larger but the plant doesn't. What have I forgotten to tell you?!

I don't think they cross with AVs. There are a lot of episcia species, well, not a LOT but considerably more than most of us are familiar with, and I think one of the ways they figure out which species various gesneriads belong to is whether they cross with each other. And NOW what did I forget?