given all this I would suggest two quality bookshelves and your sub. lots of really nice small speakers for that budget. I agree with Kal on the center. If you do want a center just get three of the same bookshelf units.
I agree with Kal -- if you are just going to have the L/R speakers flanking the TV (e.g. about 4 feet apart), and you aren't even going to have surrounds, there is no point in a center channel. 12 feet away from speakers 4.5ft apart definitely fits this generalization.
The good news is that concentrating on a 2.1 setup will expand your effective budget considerably