I can tell you that there is quite a few engines for this model. 1.9 turbo diesel, 2.0 turbo diesel and petrol and there is also another which I know is the 1.6. I do know that we have put nitrous on the 1.6 engine which is also in the Astra LX ( i think ) the customer never went over 40 bhp, the car was awsome.
( I tried telling him about the minimax to help his traction problem but he was having none of it, he loved the wheel spin that he never had before LOL )
You will have to find out which engine this model has before we give a quote because as we all know the diesel nitrous systems is cheaper than the petrol nitrous system.
Good to still see you kicking around James, long time no speak I hope both you and your lady are both in good health. Speak soon