At the moment I have a single GTX 760, and am wondering what I should upgrade towards. I am still able to refund the 760 for full price, meaning I don't need to lean more towards that. My budget is around $500, and there are a few 290x's at $500 so that is also a possibility. My case only has a 140mm, and 2 120mm fans, and my room is very small, but does have decent ventilation, which is why I am wondering if I should SLI or not.