Harman Kardon AVR235-Z 50wpc 7.1 receiver $230, you can add power amps in the future as you build your system
Athena LS-300 $200/pair full range speakers
Oppo DV-980H $170 universal player CD, HDCD, SACD, DVD-Audio.

Just a start.

Quote:
I'll be outputting everything through a PC,

If your PC has a sound card that supports 5.1 outputs, you'll be fine with some powered monitors. The Behringer 2030P is a very good value, but there are others you might consider e.g. Dynaudio BM5A. Active monitors are good solutions for small spaces where you've got line level audio (e.g. from a PC). If you're working with a bigger room, you'll be better off with passive speakers and a receiver or multichannel amp.

Harman Kardon AVR235-Z 50wpc 7.1 receiver $240 delivered, you can add power amps in the future as you build your system
http://www.hometheaterhifi.com/volume_12_3/harman-kardon-avr-235-receiver-9-2005.html
Infinity Primus P162 $200 delivered
http://www.stereophile.com/standloudspeakers/1007inf/

If your source for everything (CDs, DVDs, music files) is your computer and you have a sound card that supports at least 5.1 output, you don't need a receiver. The Behringer B2030A is an active monitor that can be built up to a 2.1 system with their B2092A active subwoofer for pretty close to your budget.

Infinity PS210 for $214 delivered.

A little over budget, but with what I proposed above would be a good start that you could build on in the future. Add the Infinity Primus P362s for mains ($440), the Infinity Primus PC250 ($110) or PC350 ($150) center and the Emotiva LPA-1 ($500).

Review of the P362 predecessor.
Another review of the early Infinity Primus speakers.