1JZGTE non-vvti or 20B-REW twin turbo?

mymmeryloss is right about that. Problems with the rotary engines are that the flame front travels on the edge of the apex seals [akin to rings on a piston engine].

Just a small bit of detonation, and you will be pulling the engine, tearing it apart to install new apex seals. Go to any rotary engine site, and ask about that if you don't believe me.

Also, I have seen two Supra engine swaps already so its already been done. There was even one for sale last year on ebay, and was a very nice looking truck. The guy who owned it drag raced the truck quite a bit.

If you really want to be different try either one of the new Ford eco boost engines. One of the new Mustangs has a 4 cyl ecoboost while you can find another in the V6 Taurus.

Or, if you really, really want to be different how about a full blown Ford Coyote engine swap.

Really different would be a RR Merlin engine, but practicality will be out the window, and its not much of a "Bolt In" What about the 1UZ Toyota engine, that's probably not been done, hang a pair of turbo's off of that.