do it yourself!!! it's not that hard. seriously, and on a head that cheap, if you mess up, you can spend like $50 and get a new one. Regardless of who does the porting, new valves aren't needed unless you have messed up ones, or are getting larger valves, obviously. You just need to get a good multiangle valvejob done by a reputable shop, as a good valvejob is where you are going to gain most of your flow anyway. New valveseals, and cleaning job on the head, and you should be set. I recommend upgrading the valvesprings if you are going for performance, in order to rev a little higher, but it's not necessary.