Well if you can get it really cheap, your psu will handle both just fine. I did some research and you should have no problems sli n' those cards with your current psu.
also..if you order a video card, they usually come with THEIR own converter from a 4 pin molex to a 6 pin pcie..so you mighta lost a few bucks there ordering your own..but oh well, can never hurt to have an extra
also..if you order a video card, they usually come with THEIR own converter from a 4 pin molex to a 6 pin pcie..so you mighta lost a few bucks there ordering your own..but oh well, can never hurt to have an extra