Sounds good, but with the super charger your gunna have the same insurance problems as you would with a GTS-t...
If your really keen to keep the GTS, then I would get the exhaust first, then mags and good tyres, and get the suspension looked at (good shocks/springs and a good alignment).
Then if you really want to keep going, get the super charger and FMIC.
Buuuuttttt, and your gunna hear this a lot, the bang for buck won't be as much compared to modding up a GTS-t....
J