I started with CSW speakers based on a Consumer Reports review (what did I know?). I had the Ensemble III, blew them up, traded them to CSW for the Ensemble II, Center Channel Plus, Surround II's, and Bass Cube 12. Not a bad starter system and easily filled my 24X16 room. If it were me, I'd just wire one of the center surrounds. I couldn't tell if you had a center channel. If not, use your left over satellite for that for now. I don't know about the subwoofer you mentioned..I don't recall hearing about it. FWIW, don't overlook an SVS. I did find that those CSW's can be difficult to integrate with a sub.
Good luck !!!