Pearcei and klotzschianum hybrids would be your best bets, although there are some "smaller" growing species and variants like P. longifolium v. hartwegii and gracile that are sometimes used to make small/compact hybrids. Additionally, if you like long petals, then you may want to seek out hybrids with P. humboldtii or P. lindenii.
As for P. pearcei and P. klotzschianum, there's a bit of a trade off to consider. These species produce growths on extended rhizomes, so while they stay short in stature, they tend to spread out with lots of space between growths. Sometimes that characteristic is exhibited in their hybrids and it means they may require a bit more horizontal space than other taller hybrids.
Also meant to mention that one way you might go about discovering new hybrids is with a site like
http://www.bluenanta.com/. You can search for a species like klotzschianum, then click on the Progeny tab, and it shows a fairly accurate
list of registered hybrids. There are even photos of some available. As for sources available in your area, that's another issue, but since I don't know where you're located, I'll skip on making recommendations for now.
