Skip the center channel for now. Like I said, don't worry about HDMI at all right now. Get a basic, cheap receiver that has a few component ins and outs. You can upgrade to a really nice Yamaha (one of the best brands for mid-priced home theater set-ups) later on. Spend your money on a nice set of front towers, small rear surrounds and a sub. As for brands, Energy makes excellent mid-priced stuff (and awesome high-end stuff, but that's gonna be out of your budget right now).
Go to:
http://www.energy-speakers.com/v2/
and locate a dealer near you.
You can get C300 towers for about $190 each, a pair of C100 surrounds for $170 and an ESW-8 Sub for $190. That's $740 for all of you speakers and about $200 for a receiver. If you're willing to spend a grand, you can have a really nice set-up that will last a year or two until you can upgrade the receiver. If that's too much, you can buy the Energy ACT6 system, which includes all of you speakers and a sub for under $600.
If both of those are outside the budget... Since you may be getting a Sony TV and like the Bravia line, Sony has Bravia complete system you can get for about $300.