Welcome mate
Power well that depends on how much$$$ you have
You can start with a 421 exhaust and a sports cat which will help it breath better ( plus you get pops and bangs if you have a tape ecu.
Then you want a panel filter, then if budget allow you can fit some cams.
As for the rear disc conversw it not necessary tbh, but you should change all the bushes for the powerflex ones makes a big difference. Im in the process of dping the same thing check out my thread