The card is about minimum for 1080p, but it will provide smooth gameplay with medium/near max settings depending on the game. You can up it to a GTX 660 or HD 7870 depending on the make/model of PSU you get. I have a GTX 650ti Boost 1GB on one of my machines with a Ivy Bridge i5. It does quite well, almost a GTX 660.
The motherboard is not an issue. It's all about the PSU and your budget. An HD 7870 requires 2 x 6 pin PCIe connectors. The other cards discussed only require 1. The HD 7850 is a sideways move to the ti Boost. Don't let us discourage you from the Boost. It will do OK for you.
Here is Tom's Hierarchy chart for gaming cards: http://www.tomshardware.com/reviews/gaming-graphics-car...
Thank you very much. This has been very helpful. I just found out I made a silly error. My monitors resolution is 1600x900. I know it's still greater than 720p but do you think the HD 7870 is still the best way to go. Or would a cheaper card be better. more along the lines of a 7770 or some othernvidia card?
One more thing. I was also thinking about limiting my RAM down to one stick of 4gb. I don't multi-task when I game so I really see any need for 8. I can upgrade if I really need to later. Any recommendations. I'm not looking to spend 60 dollars on RAM. Closer to the lines of 40 or 50, if anything like that even exists... You probably already have guessed it but i'm pretty new in building computers...
At 1600x900 you can easily get by with the GTX 650ti or HD 7850. Even the HD 7770 would be OK. But the other two choices would more or less guarantee that you could use the highest settings in most games. Here is something you may want to give a quick read as to 4GB vs 8GB of RAM in gaming: http://www.techbuyersguru.com/RAMgaming.php
Basically, they are saying that since games are still 32 bit coded, they can only address 4GB of memory. But we seldom run our machines totally void of background activity when we game. Windows is using some of that RAM, and it is constantly doing "housekeeping" activity in the background. So, while you will be fine with 4GB temporarily, you won't have a full 4GB to work with while gaming. And less importantly, you won't have access to dual channel speed with only one stick; you have to have identical sticks in each channel for dual channel mode to take affect.