I don't think there is a right or wrong one to do first. If you slap in a great GPU you will get a bit of a increase but your CPU will hold you way back. If you put in a CPU/mobo you might get a small increase but your GPU will hold you back. With that said I always do CPU/mobo first. I would Highly recommend going intel i5 for gaming. Then wait till you got a bit of cash in the hopper and pop in a new GPU.