Hi, I wanna get an ATi Radeon HD 2900 XT, but don't know if my PSU will take it. I have a 600W PSU, made by sumvision. I think this is it. http://www.aria.co.uk/Products/Components/Power+Supplies/500w+%2B/SV+600w+SilentLoad+20+%26+24%2BSATA+PSU+?productId =26842

I would also like yo know if would run either an 8800 Ultra or a GTX 260

Thanks