3uz is what I have in my ls430. It is a simply awesome engine. I would not recommend it for a swap.
Toyota is very bad about letting you in the pcm. 3uz is vvti. It has a can bus. The pcm wants communication with a lot or parts you don't have like the instrument cluster, bcm, and entertainment module. If I was going to do this, and I already learned my lesson putting a 1fz in a lv, I would go with a stand alone pcm like a haltech, megasquirt, holly or edlebrock.
Also, Its big and wide and doesn't bolt up.
Transmission choices are limited.
Aftermarket is non-existant and swap info is gonna be limited to mostly aussies.
A ls based engine bolts up to a lot of gm transmissions, although the 6 speeds are very spendy. The gm transes can be adapted to the lc transfer cases. Theres a ton of aftermarket. They are 300k motors with 400 hp easy and are super tunable. The one in my 45swb is insane to drive. Way over the top. They are small, fit well, and have been done a lot. Its a LOT easier when there are resources. Any fool, even me, can tune them with HP tuners. They are built with nearly stand alone harnesses. They have been put in absolutely everything so there's a ton of parts and knowledge.
If you have lots of hair to pull out, have a ton of spare time to fight with wiring, and no life to speak of, I would go with a 1fz over a Toyota v8. If you want easy reliable power do a LS.
I'd prefer you didn't cut up a nice truck though. Both of my LS swaps and the 1fz swap were 350 swapped trucks already. My Toyota engine swaps with 5vz and 3rz were done on 4runners with similar older engines.
I would be happy to help in whatever direction you choose.