I am working on an alh right now...
It all depends on what you are looking for.
1) full electronics as it would be in ahu engine
or
2) Mtdi setup.
Then you get to do this stuff:
The list above is a good start. I would also consider swapping in a mk3 k frame, axles, rear beam, front knuckles, front brakes.
you will have to do the following custom fabrications:
1) shifter tower
2) go pedal (if going electronic)
3) clutch pedal (as stated above a passat one can also fit in)
4) intercooler
5) piping for boost, intake, intercooler
6) gauge cluster ( convert one or use the oem one)
7) ECU wiring.
the biggest things are the piping and the wiring. I have not quite got to the stages yet of getting the engine in yet. I am still working on seam welding and putting the cage in. That and some other one off modifications that will help the car a bit...