My guess is on plastidip.... Shop around you can get it here for a reasonable cost
If in fact I'm correct here is the aus alternative that looks pretty good
http://www.evolvedcoatings.com.au/liquid-wrap/
Only thing you could do with finding the motor gav would be to backtrack through PO's to see if anyone knows anything.... or....... break out the dremel
dude seriously buy another run around for the family. I would hate to see what a zed what look like in a high impact crash... you can buy MY2000+ cars with full airbags, abs,tc and esc for under $3000 in RWC.
have a search around the forum. sirpent has some good info in his build thread. IIRC you are able to put up to 5.6L NA or 3.2 Boosted those figures are for 260z so not sure if the 240z weighs the same.
ECU wise you should be fine.