It has been done before. Driftmotion in California has details.
Was tuned on E-85. Numbers were good.
Just need a shorter water neck to connect the head to the block, bolt the 2J head on. Use the 1JZ parts from the timing belt to the short block, 2J parts for the head.
Some stuff will interchange, but that just keeps it simple. This basically includes valve covers and gaskets, intake/exhaust manifold gaskets... I'm sure you get the idea.
Then, just bolt it all up and it is a JZ engine. One that breathes and is capable of high RPM without porting or modification. Flat top pistons are working great in JZ engines, which 1JZ motors come with stock.
If you use a GE head, make sure you figure out the issue of the unique water situation before you get too far into it.
Depends on your situation and if you care about what some people think. A big point in value, is the capability to flow a lot more air under boost vs a stock 1JZ head. That theoretically should mean lots of high RPM breathing, destroking a 2JZ, instead of stroking a 1JZ (1.5JZ).