I had only heard of height issues on 7k into ke70 but I could be wrong.
Point being a 7k is a lot more findable at least in Australia as the 5k powered vehicles arent really on the road anymore but the 7k vans continued up past 2000 model year.
I think a 2.7 litre RZ Hilux motor would be a good conversion if you couldnt find much else. Might be hard to find a tall enough diff, but they really do make great torque and theyre hard to kill. Would be annoying having a useless first gear but youd get used to it.
Dont try and make a 4wd box into 2wd, its not worth it.
2azfe engines are everywhere, but judging from the questions your asking, making mounts, oil pickups and manifolds might go over your head at this stage in your modifying career. Also the required W5x box is getting hard to find. I remember when Terry tried to sell one here 5 years ago for 150 bucks, no takers. I just saw one up for $850! Makes it seem like me paying a grand to get a car with one spare was worth it.