To use an in tank pump you will have to drop the tank and have some sort of Access cover to push the pump down into. If your tank doesn't have this then that is something you will have to fabricate which adds time, effort, and cost to your build as well as complexity and possible fuel leaks.
The cheapest most practical route will be to buy the cheapest in line universal fuel pump you can find and installing it in line close to the tank, but tucked away so it isn't damaged or ripped out by rocks and debris off road. There are plenty for less than $30. Most of them will self prime. You shouldn't have any problem with fuel starvation in a landcruiser. I ran a $20 universal electric pump to run a 406 small block built to around 450hp in a 71 half ton 4wd. I didn't race my truck. I never had any problem with fuel starvation. I only had the electric pump. I had a blockoff plate in place of the mechanical pump.........My setup had a carburetor. I can't say they will work fine with fuel injection.