Well with that budget you can be looking at I7, 920 d0 CPU, either an asus p6t deluxe or gigabyte ud5 mobo, 6 gig RAM, a 275 or 4890, and a quality 750w psu, corsair, bequiet, pc p&c, that's off top of my head, can't do exact spec I'm afraid, at work, but gives you starting point