Right now, aside from FSX/P3D and X-Plane, which are sort of lacking from the accounts that I've read, there are not many options for virtual soaring.
There are two dedicated soaring sims, Silent Wings and Condor, if you can live with the prehistoric graphics. But I'm not really into Jurassic graphics.
I have seen favorable mention of the original Aerofly, and it seems to me like this may be a great area for Aerofly FS 2 development to target. From the looks of things with Condor's continuing popularity, even in spite of the dated graphics, some well-modeled soaring in Aerofly FS 2 might bring in quite a few new virtual pilots.