An engine rebuild is always ideal, but as long as it's healthy it should be ok, the stage 2 chip, injectors & an uprated actuator is a good option, they do recommend an uprated fuel pump too. as for the cam ive allways used piper 285 t2, but ive heard they can wear out quick (personally think they havn't been insalled/run in propperly) so the kent version may be worth a look at, a vernia pulley is best fitted to set the cam up. why are you replacing the head gasket? also start saving for a new turbo, the weak T2 turbo dont last long on high boost, hence lots going to the cheaper stronger T3.