Thanks rolli59, I just had a closer look at my card package, it is a gtx660 sli, I am not very good at this stuff, I'm learning as I go.
Would a corsair GS700, do the job? I believe in getting something a little bigger than needed.
SLI stands for using two cards together, SLI on your package is only there because your card with another one can be put in SLI. The recommendation stands for a single GTX660.
Corsair GS700 will do the job even after you add another card and overclock the hell out of your rig, with power to spare.