Actually its not that hard to do.
Pretty much just a top end swap, heads on up if you want to do it correctly will all stock parts. Heads/LIM,*/C/TB/L67 injectors/MAP sensor/Fuel rail. And IIRC you can use the L36 fuel rail if you cut it inhalf. If you have access to a tuner your golden.
You can do the whole thing for about $800 COMPLETE (minus tuning). You can run the 3.8 pulley if your doing other mods at the same time i.e. cam+headers.
ZZP sells the wire harness conversion kit (~$40 IIRC). Once the top end is done you just need the L67 balancer and idler pulley.
ZZP has had so many problems because they are trying to pretty much just bolt the blower on an L36.
I mean really if you wanted to do it I would LOVE to do this project again (done it 1 other time). Ed Morad lives about 45min away from me and has EVERYTHING!
People use to say "just buy a GTP" on clubgp all the time, that is such a LAME excuse! Now so many have done "what couldnt be done" anything is possible and sometimes easier that what you think.
For example everyone said (5/6yrs ago) that you couldnt run a NON-HD tranny in a GTP, well guess what. I was the first to stop that myth!