you don't need a p67 mb with an i3, an h67 would be enough. you can probably save yourself $20 or more.
also spend your money on a better gpu instead of the overkill 16 gb of ram.
you'd probably be better off with more than 250 gb on your harddrive even if its more expensive but I guess it works for now.
I would suggest a 6870 for a gpu and 4-8 gb of ram. generally with a $700 build for gaming you'd want as much as you can squeeze out to get a gpu as you can.