Maaaaatteeee!!!! You gotta keep this one updated.. I have the same plan, except mine is a petrol auto.
You could've kept it all Jeep from the gearbox back, if you don't mind auto, because the 1UZ bolts up to the AW4. Same trans as in the Lexus. I'm especially interested in the amount of room in the engine bay and around ancillaries like brake booster and heater core pipes.
Good on ya for givin it a go, and keep us all posted on progress....
cheers