Well, I know that Onkyo and Yamaha make some decent HTiB systems, but I'm not a fan of the HTiB thing. If you could extend your budget somewhat, you could put together an awesome system (not including cables) for a little under $800 shipped. Yes, it's more than you want to spend, but in this price range, $200 extra makes a TON of difference. Besides, I don't know of ANY HTiB that has 3 component video inputs (which is what you require).
This system would include:
4 BIC DV62SIB Bookshelf speakers from Amazon
1 BIC DV62CLR Center Speaker from Amazon
1 BIC V1220 Powered Subwoofer from X-10
1 Pioneer VSX-815-K Receiver from JR, recently reviewed at
Audioholics
You can find the Pioneer cheaper than JR online, but buying from JR (an authorized dealer) insures that you get the warranty from Pioneer. And besides that, unless you hit up ebay, JR basically is the cheapest price online ($249.99 with free shipping).
This whole setup comes to $787.85 and as far as I can see, would kick the pants off any HTiB.