It's a very bad idea to mismatch the center and mains. Either match the VRC with Boston
VR1s towers (I know you don't want towers) or go with the Polks and a Polk CS20 center. I'd also give a listen to Infinity's Primus line -
P163,
PC251 center,
P153 as surrounds. My personal taste is 1) Boston VR; 2) Infinity Primus; 3) Polk but your taste may be different and the front ported Infinities will be easier to place. I'd also stay with 5.1 in an apartment.
For an apartment you don't want to be ticking off the neighbors with deep pounding bass. I think until you get into a house that I'd be looking at something clean like a
Hsu STF-2 sitting on an
Auralex Gramma but I'd measure the room and then double check with Hsu Research. The Gramma will isolate the sub from the floor and reduce the likelihood of angering neighbors.