one other thing that might be worth considering. The stage 1 is a Morgan supplied product and therefore if there are any warranty issues or if you get stopped for noise you can say its a standard factory option. If you go G56 then get stopped you have to argue the legality. Further it might be worth emailing or checking with Morgan that G56 won't be used as a way of getting out of engine or drive train claims later - regardless of the actual power changes.
Insurance might also be easier if its Morgan as again its factory fit so to speak.
I have the Stage 1 and am very happy with it - though I had heard that there might be supply issues. If G56 are being factory fitted to cars of course then no issues anyway.
