well, I wouldn't shave the head, your compression ration is already going to be somewhat high and you probably want to use pump gas in this car.
Short of cam & valve train upgrade and some port & polish... there's not much in the cheap category that you can do.
You could do some research and learn to port & polish yourself but you still need the tools and if not done properly it can hurt performance.
I'd bolt the head on and put the $/effort elsewhere like suspension, wheels/tires/ex or si tranny etc.
The tranny will make a big difference in acceleration
