What he said about upgrading, don't buy anything now and get it later, but if you have to get it now then what's your budget and where are you in the world so we know what sites to use.
everyone on this site in the uk seems to use overclockers.co.uk, so we know that this site is trustworthy and a good deal, and they also offer some decent combos and all too from when i've looked there.
Though you miss out on .1GHz, which is pointless and obtainable by a simple OC, and memory is 1333MHz, but with lower timings, so it will work out not noticeably slower, you get a much better motherboard.
Overall, performance will be the same, but buying separately saves a few £, and you get a better mobo