Now for the bad news... since sailplanes and gliders have been neglected for so long by Msft, there are, well, NO models available anywhere! I tried downloading the old ones available here at simviation under Gliders/Ultralights which were designed for the early FS versions, but many of the guages are not supported and the experience annd visuals are quite bad in FSX :'(
So, calling aircraft designers... give us some sailplanes PLEASE!!! flexing wings, winglets, motor gliders, negative flaps, ballast, its all there! Go for it!
...How about designing s flying eagle (its beak could be the canopy)

Think also of building a thermal hunting guage too -- something with color-coded VSI sampling history (that fades with time) to help provide a visual representation/track of lift and sink as one thermals... that way the unrealistic sim thermal visuals can remain off and we can get down to serious thermal hunting and long distance soaring flights using the right instruments. I can't wait!