I was wondering if I would be able to buy a SATA III add on card that can get the full potential out of an SSD. To my knowledge it would have to be x4 or greater. Can anybody recommend me one? I'm just being cheap and not wanting to buy a new Mobo.
Yes, you need to have at least a PCIe x4 to get maximum advertised speeds of the SATA III SSD. But those cards are not cheap, look at the cheapest one from newegg for $70 http://www.newegg.com/Product/Product.aspx?Item=N82E168..., and the three reviews are not good. As I know sometime it is not guarantee to work well.
My point is no worth that you put down that $$ for the card and just buy the SSD. Even your MB only has SATA II port then you are ready to get the SSD, and you will enjoy it.