Motherboard: Gigabyte GA-78LMT-S2 www.newegg.com/Product/Product.aspx?Item=N82E16813128504
PSU: Antec BP550 Plus www.newegg.com/Product/Product.aspx?Item=N82E16817371016
Ram: 8GB DDR3 ram
CPU: AMD FX 4100 Quad Core 3.6Ghz www.newegg.com/Product/Product.aspx?Item=N82E16819103996
Are these compatible together? And which type of graphics card should i get to play BF3 smoothly?
Ok let me start by saying that I would suggest rather looking at Piledriver instead of Buldozer...
Its newer and faster, also sorts out many issues(that effect gaming) that bulldozer had.http://www.newegg.com/Product/Product.aspx?Item=N82E16819113287
That is the Piledriver equavalent of the 4100. Its 20 Bucks more but A LOT more worth it, otherwise you would just be better of getting an Intle I3...
BUT the 6 core 6300 is only a little up from that, so keep that in mind...
This is it... 10 Bucks more for 2 extra cores.http://www.newegg.com/Product/Product.aspx?Item=N82E16819113286
If you decide on either of those 2 you will also need a better board that support these :http://www.newegg.com/Product/Product.aspx?Item=N82E16813128553
Thats 10 Bucks more after rebate...
Now if you insist on the older bulldozer because your budget does not allow you to spend more, rather get the 4170, its already much better than the 4100 and you can use it with the board you already chose :http://www.newegg.com/Product/Product.aspx?Item=N82E16819106009
Ok now to your original question...
How much are you willing to spend on a graphics card?
For that matter what is your total budget? Do you already have the other parts and what RAM is it exactly?
What resolution is your monitor?