I suggested that he mill the head because you can do that without removing the engine from the car and disassembling it; a hell of a lot of work. If this can be done with the engine assembled and in the car, I am unaware of it.
Milling the block is the better way to go IF you have the time, patience and help to do the job. Milling the head is a whole lot quicker and easier, though not as good, overall.