I am buying a hahn stage 1 kit from a member of the board here. I have already started to buy a few things precautionary for my car. The things I have bought already is. Autometer Phantom, Boost Gauge, Air Fuel, and Fuel Pressure along with the 3 gauge a-pillar. I also bought a Greddy Turbo Timer for the car too. What other things should I buy as precaution? How important is the oil pressure gauge rite now at stage 1? Help is greatly appreciated thanks guys.