Hey,
If you got the right powerfc you should be able to just plug it in. It says on the manuals to run the car for 10mins with nothing on (Dont touch any pedals either), then 10 mins with the defroster on and then finally 10 mins with the AC on. You will now have your base tune on the
ECU. Now drive very carefully to your tuner of choice. I went to All Star Garage, great people and a great tune. :-)
From my experience tunes go from $400-900+
Oh, and i believe the MY99's have weak AFM's. The Z32 is stronger and has a wider band reading. Therefore better for you and better for tunA!
Good luck!