Speaker recommendations?

I am getting a Denon AVR-589 and need to replace my current speakers. I need a stereo configuration, possibly upgraded to 2.1 later, bookshelf, will be in my 10*10*8(w*l*h, carpeted) room, need to sound good with music such ass Tool, Isis, Sublime, Fall of troy. I'm young, can you tell? I would like to spend no more than $300, and these will be wall mounted, so <20lbs. I am considering a used pair of B&W 685 equivalents. I've also heard PSB and Polk would be good for what I'm doing, but what more specifically. Also, my source for everything will be 196kbps AAC files through s/pdif digital from my computer. Any suggestion, comments, questions?
Also, I would like to have somewhat of a big sound out of them.
listen to some paradigm speakers they have several models that might be of interest to you
If you can buy a pair of B&W 685s for $300.00, man go for it. Rave reviews. You could not do better than that IMO. Polk is a mass marketed speaker. Go for the 685s. No brainer.