I'll assume you want the latest, which is 1155. For $355, the 2500K with asus P8P67-M Rev 3.0 is a good starting point. If you have less to spend, you can skip the sli option and get a board for about half what the asus costs. I also saw a used 6950 1156 for $50 on craigslist today. With a low end board, you could get the pair for around $110, which would be better than buying another 775.