Yes, even if you invest in a new motherboard, I wouldn't risk damaging it with that PSU.
As far as the PSU goes, It isn't as important to stay brand name (in my opinion). I would say get something in the range of 500watts (450 should do), but more importantly, at least 24A@12v+. Some power supplies have DUAL 12v+ lines because it is so imporatnt. So if you have two lines of 18A's, that of courser is sufficient, as long as you dont use all of the molex connectors on one line, and none on the other
Glad we have some sort of a resolution, good luck and PM or AIM me anytime!