Benchmark Mayhem This section is for you benchmark freaks. Wanna show off your 3D Mark Vantage scores with your brand new GTX 295 SLI or Radeon HD 4870 X2 Crossfire in that Intel Core 2 rig? Then this is your section!
A name brand PSU isn't essential. Sure, they tend to be better quality and i know that clockers/tweakers swear by them, but i use a no-name and it does me fine. I'm sure many others are the same.
Why don't you get an extra 256Mb stick and see what happens? If you start running out of power (which you might not), then get a higher output PSU. You could get a no-name(much cheapness) and see if that does the trick. If it does then great. Then, if you still want a topline PSU, you can save for that, get it, swap it out with the no-name and then you would have a back-up PSU as well.
It would be a shame not to see what your card can do.
Edit - Just to mention that there is a Sticky at the top of this forum about low scores and also this one on the Futuremark Forums.