gcsdx10

I have an intel h61ww mobo with 4gb ram and nvidia gtx 560 (1GB) gc. Is SLI possible on this mobo? I have an old zotac GeForce 9600 that I'd like to use if possible. Should I upgrade my RAM too? Will there be any compatibility issues between the 2 gc's(DX10 and DX11)? Need a swift answer. Please...