Sorry i thought you were one of those random posters before the edit.
GT640 is an entry card, no guts at all. The 7750 is by far a superior card albeit wont be anything cutting edge above the two consoles.
http://www.tomshardware.com/forum/357477-33-gigabyte-7750-good-enough
I think you'll get more enjoyment out of a console all things considered. Depending on the games you like as well.
IMO, if you don't have the WII-U yet, maybe get that instead. Mario U, Mario Kart and Donky Kong Tropical Freeze all awesome games and maybe save for a better GPU down the track.
You're pretty much going in blind, if you choose console both have their own purpose and exclusive games and PS3 plays Blurays. I hope you do get more replies but usually not many, unless you've posted else where its not going to be much of a decider is it?. Money doesn't grow on trees so do yourself a favor and research or you'll regret it.
If i have to choose, PS3.