There is no need to port/polish it as that intake will more than outflow your stock heads. If you're definitely going to upgrade the heads than some port work might pay off. I had the same intake and am using a 65mm tb but I regret not going with a 70mm.
70MM on mine, is a great match. I regret not getting the lower port-matched to my AFR's though. Planning to have Tmoss open her up for me soon, just need a tad more suspension work first.
I would definatly not do the port work to the intake. Your stock heads kill your power. You cant even stick your finger in the exhaust port of the head there is that much restriction. And if I were you i would spend a little extra money and buy a set of trick flow heads or a set of afr head. You will gain a little more power out of those that the gt40 sluminum heads.
I'd say definitely go ahead and get it ported since you're planning on swapping heads later. One less thing you gotta worry about then. The 70mm TB will really pick up some ponies when combined with that intake.