I think that would work just fine. Surrounds exactly matching the fronts aren't as big a deal as all the fronts matching.
As for the fronts matching, I am approaching the overall dream setup in stages. Stage one is the four new matching surrounds and the (matching?) new center. Stage two is new tower speakers up front to match. Stage three is the new pre/pro and amps or A/V this fall (I'm waiting for the DTS Neo:X). Stage four (next Spring) is matching "heights" and matching "wides" speakers. Then, stage five is the second sub (I'm lusting after the EP800 v3 Subwoofer). All said and done, 11.2... wallah.
