"Jacob":
I don't think I would have a problem in selecting either the Infinity Entra or the Polk Audio "R" Series Speaker Systems (assuming both of them are going to be 5.1 or 6.1 Surround Systems).
Now.......... as for the receiver???? I think that's a different story altogether. If I am on the fence, and if I was given a choice between a JVC and a Sony Receiver, I think I would opt for the Sony. Otherwise, if I was in a position to spend more on a receiver, then I would opt for a Denon or a Yamaha instead.
I am getting ready to upgrade the sound system part of my home theater as well, and right now, I am looking to combine a Definitive Technology ProCinema 60 6.1 Speaker System with a Yamaha RX-V740 Audio/Video Receiver. As far as a speaker system is concerned, if you are not already too hung up on the Infinity or the Polk Speaker System, you could do well to consider the Definitive Technology ProCinema 60 Speaker System as well. Like "Slappy" has said (and I can confirm what he has said. I have went down to Myer-Emco (an "upper echelon" audio/video chain store in my area (which is in Washington, D. C.))), they are pretty good speakers for the money. You might want to give them a try as well.
Regards and Good Luck...........
--Charles--