Godofwar, if you can stand the difficulties of running Lion on AMD, you should stay on Snow Leopard. It's not the latest and greatest, but it's far better than anything Windows can offer (well, i didn't use Win8 to know better) and run great on AMD!

Lion, as i told you, takes a lot of effort to run stable and will run only 32-bit (that means no original Finder, no Xcode, no 64-bit cool game etc etc etc)., unless you have a Bulldozer FX-Series CPU.