My advice is forget 5.1 for now and start with a good quality 2.0 or 2.1 system instead.
Option 1
Two Infinity Primus P362 tower speakers for about $400 shipped. These commonly go on sale for as low as $300 a pair shipped. They do need some minor mods to really make them great but it's not hard. WmAx posted some instructions on here a while back. For the receiver I'd look at a refurbished Onkyo
TX-SR507 for $240 or better yet a
TX-SR607 for $320 shipping. Later you can save for a sub and the matched PC350 center and P162 bookshelves as surrounds.
Option 2
One pair of
Behringer B2030P bookshelf studio monitors for $131/pr shipped. Later you can add two more pair to build out a 5.1 system (plus a spare). Again WmAx developed cheap and simple DYI mods to make these inexpensive speakers sound like speakers costing 3x as much. Add a $155
Dayton 12" subwoofer, and the Onkyo TX-SR607 and you're styling.
Option 3
If you absolutely must have a home theater in a box package deal then the only one that I would consider is the
Onkyo HR-S7200 for $600.
Mini-review.