Ive talked with Graham about it. its the guy that made the 1jz-gte VVti conversion. Theres alot others that has done this on different forums thou its not complete topics or missing pictures, but to make it easy i can list a few things that u have to do.
* 1jz-gte or vvti engine.
Gearbox: theres 3 different u can use i think. its the 6speed getrag one that is verry expensive and hard to source of what i know. and theres the r154 and another one.
* U will need an 3rd part ecu i think something like autronic, microtech, motec would work nice, surely it depends on what the mappers around u can program.
* Custommade engine mounts is a good investment if u want a good weightbalance of the car. otherways u can use the soarer mounts i think.
* Intercoolerpiping, exhaust.
* mate the propshaft with another one depending on gearbox.
Tbh the tricky part is the electrics, the wiring, u will need some wiring diagrams, and some kind of basic knowledge. And its not a walk on roses making these 2 ecu working together, ur dash will look like a disco :)
Some guy just switched the fuelpump for a different one and that made the fuellight start blinking, seems the is200ecu doesnt like other parts :)
Ive havnt digged so deep into this conversion yet but i know that it will take alot effort and beating to get it working. Thou as Graham and the others say *the electrics, Wiring etc is the fuzzy part* thou im gonna take a really deep look into the diagrams one day to see how the is200 wiring looks since its like 5 computers wired together it might be fun :) (ive heard theres like 18 pages)