I have a guy who has done a few around Melbourne coming up to Toowoomba to complete it once I get all the bits together. This guy does remapping and ECU tunes and he has a plan.
Good you have a dude who has done it before.
The P2's electronics are very fussy around neutral safety and reverse lock-out.
If you have an S60 manual and the electronic modules that go with it - then you're off to a good start...
Do keep us updated...
About sourcing parts - if you have no luck here, try sourcing from UK wreckers (breakers) there a lots of manuals over there. The postage is the $$$ part.