In that price range, I'd shoot for something like this:

http://www.bestbuy.com/site/olspage.jsp?skuId=8504692&type=product&id=1186004964722

Yamaha is the best out of the beginner/consumer grade brands (sony, yamaha, samsung, etc.).

If you try piecing together a system, for that price range, you're going to run out of money in a hurry, and most likely will end up with speakers that don't match each other very well, get overpowered by the sub, etc.

Then for a future upgrade, a high quality center channel speaker will make the most noticeable difference in any home theater setup, as most of the dialog of a movie comes through the center channel. The clearer/crisper that speaker is, the better everything will sound to ya'!

Whatever you do, don't get a cheap speaker system, a cheap receiver, and a high-powered sub...that's what a lot of people do, 'cause they think they'll get the most bang for the buck w/ a big sub, and just "make do" with cheap speakers... That's a good way to get some really shitty sound in movies... The bass has to be huge when appropriate, but low and clear sound, too. If the speakers can't overpower the sub for dialog scenes, you end up with an annoying low rumble all the time that can't ever be matched...you end up not hearing the rest of the movie!