You need to convert to efi set up so fuel tank and lines will be needed.

Gearbox well depends on power really..

180 bhp standard cvh box with diff

240 bhp stage 2 box with quaife diff

350 bhp stage2 + box with quaife diff.

400+ st170 or mtx box with quaife diff equal length shafts.

wiring loom not sure as im not doing mine... but im sure if you ask on here or fiestaturbo.com more so someone will help out..

Cheers for the comments of mine mate