I have to disagree...the stock radiator is far from insufficient for that setup. An aftermarket radiator is ideal, but you can find other things to spend $350 on. Make sure your fan works and you'll be fine.

I would check the classifieds on HAN and HT, maybe Ebay, and pick up a barely used OEM radiator for $50-$100. You can also get a new not oem replacement for not much more.