You say "buy a new pc..." if you build it yourself, you can probably have both, and better other parts as well.
Otherwise, for most things I'd take the FX + GTX760 also. If I were going to play more CPU-dependent titles though (like MMO or BF3 multiplayer) I might go for the i5, but try to stretch my budget to a GTX650Ti Boost Edition.
yes, i'm building it by myself, but i wrote i'm buying it, sorry! i will not play multyplayer a lot, and mmo neither. i'll play games like cs:go and tf2, gta and mostlu trials evolution. but i also want to play next gen games good. i think i'll take the amd solution, it's cheaper and better than the intel solution. what about the psu, is a 550w enough?
A quality 550W PSU is sufficient, such as the Seasonic "G" series or the Rosewill Capstone. A modular Corsair CX-600M would be an acceptable cheaper alternative. Do not get a non-modular Corsair CX though; they are all made by CWT for Corsair, but the non-modular models use some inferior Samxon capacitors that do not like heat and are known for early failure. I would not put one in a gamer.