DDR3-2400 (higher is better, but make sure it's DDR3) CL11 (lower is better) RAM? Just get something that's good enough and looks great with your system - black or blue heat spreaders and black PCB on the RAM goes well with your current setup. Don't go with bog-standard bare DDR3-1600 CL11 RAM - in addition to being slower than the CPU would have liked it - you want at least DDR3-1866 CL9 or equivalent faster RAM, they also look really ugly. And since faster RAM at 1866 CL9 is really darned cheap, there's no point getting the bare minimum. If DDR3-2400 CL11 RAM is too expensive, try DDR3-2133 CL10 or DDR3-1866 CL9.
Also, you should try to get the RAM in pairs. Kits of 2 should be more than good enough. Is your boss going to game on the system? Then a kit of 2 8GB (16GB) will work, otherwise opt for a kit of 2 4GB (8GB).
Video card?
Also, you probably should also get an aftermarket CPU cooler from the likes of Corsair, Cooler Master, or some other company you'd know. Even if you're not overclocking, the Intel stock cooler won't let your CPU perform at its best, especially during summers.