my 7900gtx is coming tomorrow and so is my x24800. the case i am getting is this http://www.newegg.com/Product/Product.asp?Item=N82E16811144090 which is the aspire x navigator. it comes with a 500W power supply. do you think that will be good enough to run both of those with asus sli deluxe mobo and corsair xms series ram? the 7900 is not overclocked from the factory and i dont think i will be doing ne major overclocking with the cpu either. So can i use the PSU that comes with the case?