Go for the Toyota diesel... The 1KZ-TE is by all accounts a good motor. Especially if you have a half cut, it will NOT be a hard swap, assuming of course you have the tools and some mechanical ability. My swap is not a 1KZ, and I had no half cut, and even it was not that hard; there is just a lot of little semi-difficult stuff to deal with. You just have to take your time.

'87 Xtra Cab, 4wd, 22r, 5spd
'92 Xtra Cab, 4wd, 2L-TE diesel swap, 5spd
http://toyotadiesel.com/forums/showthread.php?t=2502