Well i'm assuming your Z32 is N/A I hope.
I would definately go for the RB25 if you were planning to do this. There is going to be some major fitment issues, be careful of the turbo and downpipe on that side.
However, I have seen a 2JZ into a Z32 but this was in the Middle East from those TopRpm.com guys.
If it makes you happy, go for it, but try at least going the RB25, RB20 seems a little too weak. I mean the 200ZR came with the RB20, but do as you please.
Good luck!