In addition to the above posts that I agree with, I would definitely budget towards room treatments, especially in such a modest room. A bigger room could afford you longer delays, less modes, and less resonances. If you want the best in terms of performance in this room, I suggest you use plenty of bass traps, in addition to addressing reflection points. You will have to do a lot of fine tweaking of speaker positioning and listener positioning as well. If the room's acoustics are at least OK, the addition of such treatments can possibly afford you a much easier time in finding the final positions.
Some other things to consider spending on with this healthy budget. Some HT seating. If it pleases you, and I bet it might, some transducers attached, like with those made by Buttkicker or Earthquake.
You might want to investigate the possibilities of dipole or bipole surrounds. I am afraid that BW 800 series could be overkill in such a small room like that. Like really overkill, and could arguably* be a waste of money.
I would vote for bookshelves + sub for the front. If you can swing it, go with three identical bookshelves, all upright for the front. Even better is if you can get them on the same plane, but that's usually impossible to do without compromising where the display is at VS the ideal height of tweeters.
-jostenmeat
