Ultimately, I would suggest speakers which:
a) sound best to you
b) fit your budget
c) are aesthetically pleasing to you (and the significant other!)
Now my personal opinion: I am assuming you are developing a home theater environment from your mention of a center channel speaker. If that is the case, the Studio 20s would be a good choice coupled with the obviously forthcoming subwoofer. This combination will allow greater placement flexibility (independent placement of your low frequency source) than a floorstander. As a bonus, I can imagine this combination would perform well for 2 channel listening too.
While the Polks may provide enough bass extension to perform satisfactorily in a 2 channel system, they likely wouldn't supply the same 'WOW' factor that a dedicated subwoofer will.
a) sound best to you
b) fit your budget
c) are aesthetically pleasing to you (and the significant other!)
Now my personal opinion: I am assuming you are developing a home theater environment from your mention of a center channel speaker. If that is the case, the Studio 20s would be a good choice coupled with the obviously forthcoming subwoofer. This combination will allow greater placement flexibility (independent placement of your low frequency source) than a floorstander. As a bonus, I can imagine this combination would perform well for 2 channel listening too.
While the Polks may provide enough bass extension to perform satisfactorily in a 2 channel system, they likely wouldn't supply the same 'WOW' factor that a dedicated subwoofer will.