JimX, I have my redline set at 7500, and tend to make peak power around 7200rpm, and don't get much drop off in power after that. Most stock GTS-t's tend to drop off quite alot after about 6900rpm, but after I change a few things to my air-flow setup, including the Greddy plenum (await's Sydneykids flamming) the power doesn't drop off nearly as much.
I've had the 7500 limit for over 6months now and even with 400+rwhp is hasn't killed the pistons. My advice is once you have the PowerFC in then check to see if the power drops off, if it doesn't then you can push the limiter out a bit further.