Graphic card help (bought barebone kit)

Hello all ! I have a quick question.
So i bought a barebone kit from tigerdirect 2 weeks ago, it included:

Amd 9500 quadcore phenmon
650 mobo
3g ram
win vista premium 32bit
ati 2400xt
and a standard bestec 350 or 400w psu i believe

Anyways i was wondering if you guys could find a graphic card that will best fit this setup, keeping in mind i want to max settings in WoW(including shader quality) which i have troubles with now with the 2400.
I also want the card to be able to run with this budget psu for now.(i will purchase a psu near christmas)
Now, all my gaming life i have had ati cards, i would like to try out a nvidia card of some sort.
I was thinking the 9800gt or 9800gtx, i dont need a top of the line card...what do you guys think ? Will it run ok without frying my system on that psu lol or should i just wait all together and get the card and psu together.
Thanks a lot...