Home Theater Speaker Help

[jmb]

Hello. My first post. I have been looking around here a while and need some help. I have a Sony STR-DG920. I want to upgrade to 7.1. I have a Sony SS-V531H 5.1 system now. I was looking and found a good deal it think at Ciricuit City. A Polk RM510 system which has 2 RM7, 2 RM8, 1 RM8C and PSW110 subwoofer. I see alot of the system have a least 2 floor speakers. I was thinking of geting the RM510 and add some floor speakers to get 7.1. What do you guys think. Does this sound good to you? Or is there someting better. Any question please let me know.

Thanks, jmb