Since your surround system will be for movies (as opposed to hi-rez music), you really don't need to worry about matching the surrounds. I've been using throw-away Kenwoods for surrounds with my Paradigm/SVS system and couldn't tell the diffrence when tested against paradigm surrounds.
Therefor.....
if you like your CV mains, I'd look for the matching center channel, then check the local used market (pawn shops, etc) for any good condition stereo pair to use for surrounds. The front three and your subwoofer are the critical speakers for HT.