look into the Nistune boards. You can tune the stock ecu, just need to get a chip put into the stock ecu. over in the stagea section it has been discussed over the last week or so, see link. S2 stagea autos use the same ecu as the R34 auto. and at around $300 for the chip installed, then all you need is a tune, its a good option. i'll be doing it soon.
http://www.skylinesaustralia.com/forums/Pi...us-t105859.html
the last 2 or 3 pages