Get a 500w psu for a 7850, xfx, antec, corsair and sesonic are all great brands. i woukd also add another 4 gb of ram when you upgrade to i5 + gpu. Other then that, great build. Just don't expect to game on that celerons integrated gpu.
Most cpu come with a decent cpu fan and seeing as your build won't be very heat intensive I would say take out the cpu cooler and add the money to other places. Also as far as your mobo goes it is way to good for the rest of your rig so I would scale that down and add it to other places. Some places that could use the help is your hd and probably your power supply depending on the graphics card you pick.