RedLineGTR - Haven't tried to source it personnaly, but I beleive you buy it from BP at a 'cleaning' agent.... refer to other posts about it.
SMB315 - Yes you can run more boost, but you'll still be limited if running the standard ceramic wheels.
bigcarl- Yes I can and have tuned several link ecu's and I know why Ian won't tune them, for the same reason I won't recommend them. I only tune them if someone already has one. The older microtech's were fairly neanderthal but the new ones have full map matrix tuning on fuel and pretty good ignition mapping. Wolf looks very good on paper, only done a couple of these though with mixed thoughts. Personnaly my favourites are re-mapping the standard ECU's just wish i could do the RB25's economically.
Also, for reference my old 180sx was running a pretty much standard setup with a remapped ECU, 1.1 bar of boost, and a 20% Toluene mix... Result = 13.5 @ 98 MPH