For stability, an Asus board would probably be best. As far as the video goes, the 7950 smokes the 1900XTX (I have one of each) but when you throw budget into the equation, the 1900XTX is a good buy.
If you need a
PSU check out Aspire. I got one of their 680W and the voltages have been rock solid with enough overhead for future expansion. The price is right also.