My mate is giving me 3gb of ram to add to what I have but I can only put 4gb in that should be enough
4Gb will be just barely enough. But since the board uses DDR2, not much choice.
Also, the Q8300 is actuall enough to run the GTA V on low settings.
So adding an GTX750Ti would make you be able to run it at low settings.
It probably won't run Max Payne 3 on high but Medium at least.