you will more than likely have to change to rack and pinion steering, i have a 240C with an underbonnet area the size of a kingswood and i couldn't make it fit around the steering box - so i had to use a commodore setup.
you might be able to use a fiat X1/9 setup, they're very compact units and i have one in excellent condition incl tie-rod ends if you want it.
the 1UZFE is basically a 700mm cube, so if you can make that fit in a 1200 (ooh, that's gonna be tighter than a frogs arse) then you're a magician!
the exhaust ports point downwards at a 45deg angle on this engine - straight at the engine mounts. with little to no room left after the r&p conversion + new engine mounts, i'm thinking you'll have to mount it using an engine cradle off the front of the 'chassis'.
you'll also more than likely need a front sump engine. there are three types - front, centre and rear. the rear mount will foul on tyour steering components, the centre mount will foul on your crossmember so that only leaves the front mount.
you'll need a good radiator, like a 180B radiator and shroud, or better yet and alum radiator (the std soarer ones are too big to fit even in the 240C) but that's $$$ and a last resort option. the 1UZ isn't a hot running engine and relies more on oil cooling than water cooling. that said, you'll still need a 16in thermo.
oh, and the oil filter will need relocating. luckily, the factory units are already remote, so just unbolt the oil filter adaptor from the engine and modify the std steel lines to accept barb fittings (ENZED did mine for $120) and run flexible oil line to wherever you want to mount the oil filter adaptor (mine's up a little high in my engine bay for easy access - prob not the best place but i warm it up before i drive) in the engine bay.
other than it PHYSICALLY fitting, these are your other obstacles.
if it works, post pics for me to drool over.