Hey, i have two questions. First, currently I have a 550 ti and I NEED an upgrade. Should i buy a 770, or a 780? The 780 is much more expensive then the 770 so i was wondering if it would be better just to buy the 770. If you do reccomend a 770, please tell me the exact name of one I can find on amazon. I want it to be the best 770 I can find, and im only using one monitor for those wondering. Secondly, would putting my 550 ti and 770/780 on an SLI increase my performance massively? Or will the 550 ti bottleneck the whole system? Copy and pasting a link to a guide on how to setup an SLI would be cool.