Just my opinion.. but if your going to mill the head its a good idea to re chamber the dome also. By only milling the head your decreasing the squish band and still keeping the factory junk dome profile. By only increasing compression, the gains are minimal. With a properly milled and re chambered head your getting the correct squish along with a proper dome design and higher compression. Mull engineering sells modded (cut and rechambered) heads. In stock and ready to go at a good price. Or.. I'd go aftermarket head and domes. I'm not a fan of only Milling/decking the head.
Also keep in mind other site sponsors like Wildcard, FAST, Passion and Redline along with Mull engineering can cut and rechamber your stock head at a affordable price too. These options will give you a more custom setup to your motor and riding style.