My opinion is that you need to rethink what you are saying. A 'decent' surround setup runs at a minimum about $1,000.00 - Then you can start looking at good things when you are running several thousand dollars. Excellence really costs a lot of money.
When you have the money for a Yugo - you don't start asking about what type of Corvette you can get.
With $400.00 you want a package. WHY? Because a company can combine a good mix of value put it in ONE box and ship it to one store and the store only needs to track it ONCE. That means a lot of savings to the store and to you. You will find home theater in a box systems all over the place, and Best Buy isn't a bad place to buy from. I personally got my first HTIB system from Sam's Club. It was about $300.00 and served me well until I could afford something decent.
With that said - you do have the separate receiver & speaker package as listed above.
ABOVE ALL ELSE: STAY AWAY FROM BOSE
The Sony speakers may do well also: SAVE367T
But, that puts you well above 400 bucks.
Now- in a HTIB package, you have a Yamaha, Sony, or Pioneer package, none of which are total junk. The Yamaha package at $285.00 likely gives you more quality than you are going to find anywhere else for your 400 bucks.
Of course this is all my opinion and it's your money to do with as you please.