So something like this should work? I know it's not the base 750, but it says 400W for power requirement, and I don't think RAM takes up that much (although one day I will go 16gb or even 32gb, but can barely imagine the need).

http://www.amazon.com/EVGA-GeForce-750Ti-GDDR5-Graphics/dp/B00IDG3IDO/ref=sr_1_1?ie=UTF8&qid=1443903161&sr=8-1&keywords=nvidia+geforce+gtx+750