hmmm... the x1900xt definetly doesn't need 30amps on the 12v rail(s), I would probably recommend you three products. If you want the psu to be quiet go with the seasonic s12 430w. It has 29amps on the 12v rails combined, and it very quiet and efficiant. It is fairly expensive ($80?) but worth it for most people. My second recommendation is the enhance 5140gh. It is a great value with 28amps on the 12v rails, very good efficiancy and very stable. It is around $68 shipped. The last one is a budget recommendation. For $55 shipped you can get a fortron/sparkle fsp400-thn. It has 28amps combined, but is a budget psu, so it's a little louder, not as efficiant and not really pretty. (The enhance and the seasonic sport cool black finishes😀) It should do the job though. Good luck!
EDIT: dBtelos... the xconnect has dual 12v rails, does it not? His might be the v-series. Those only have one 12v rail. Not a good psu. 'course, it might run the rig for while, but ultras are loud and supposedly their depreciation rate is high.