I'm looking to get 2 bookshelves, 5.1 or 6.1 receiver, and a sub for this amount of money that will be worth keeping and upgrading through the next few years. Currently I'm looking at Polk RTi38s for about 250, a Yamaha HT-5630 receiver for about 200 and either a WM500 or WX700 Sony sub. What changes would you guys make to this setup? ANY advice is HIGHLY appreciated as I'm very new to this market. PS the speakers will be used in a dorm room until june then a slightly larger bedroom the next. They will be used for my PC and for my PS2.