I think with two 670s in SLI it's pretty much guaranteed you'll be able to max out any current game at high resolutions. 
I'm guessing you're talking about the SLI bridge which links to the two cards together, right? Sometimes the cards come with them already, but if not, this is what you need http://www.newegg.com/Product/Product.aspx?Item=N82E16816101655
I'm guessing you're talking about the SLI bridge which links to the two cards together, right? Sometimes the cards come with them already, but if not, this is what you need http://www.newegg.com/Product/Product.aspx?Item=N82E16816101655