Saided18, my car is hoding up very well, I run it at 8 psi and did some AutoX competition and don't have any problem with my car. It is just runing a bit too rich but since we have advance timing, but it's saffer that way.
I always run it on high octane gaz (92 or 94), do oil change every 4000km with synthetic oil. I also have A/F, Boost and EGT gauges to keep an eye on what happening under the hood.
The complete custom kit with 2 1/2 complete mandrel bent exhaust with the installation cost me around $6000 Canadian. I said around because I add some extra gauges and steel braided oil line after the kit was installed.