Some serious advice needed regaurding 2.0 8v

[derv-burner]

Hey, i have recently bought a donor corsa b with a 2.0 8v engine.. donor car has no m.o.t or tax.. i have planned to lift the 2.0 out of the donor car and place it into my 1.5TD corsa along with all running gear.. However the wiring loom on the 2.0 luks abit rough and the speedo, rear indictors etc arent workin on the donor car.. I was wonderin if any1 wud have any advice on this,, Can u buy new wiring looms for a 2.0 8v of the shelf..??? any other advice wud be greatly appreciated thank!!!