I have the r-5650-s in wall surrounds, I have had them about 3 years they are good quality and sound great in a poorly set up system. So in a good setup they should sound even better but that is in a surround configure with only 5.1. I have not herd the in wall fronts you are looking at, but I do have a buddy with a room about the size of yours if not bigger and he is running cheapo in walls that I think are even smaller then the Klipsch ones and his sounds pretty good. I don't think you would be disappointed with them but like CECAA said if you go with floor standing you won't have problems with your walls when and if you want to upgrade.
I went 50/50 I have floor standing speakers on the l/c/r and the in walls for surround maybe look into this with some nice reference fronts.
Hopefully this doesn't confuse you. Good luck with your search, I think the danely clone for a riser would be a great idea.