You can support up to 4 RAM sticks with a total capacity of 32 GB. The only DDR3 sticks that I have seen that would max that capacity if EEC-buffered DDR3 sticks that rum something like 200 USD a stick.
Short answer, 4 DDR3 sticks. assuming the link below is the right motherboard. http://www.newegg.com/Product/Product.aspx?Item=N82E16813128476