Sounds like quite a project. You may want to consider a vehicle that doesn't need quite as much modification to begin with (at least a 4WD Amigo if that is your goal) so as not to get bogged down. We may make it look easy by posting our progress, but it's many hours spent trying to make things work; the easier you can make it on yourself, the better.

You don't need a lift pump for the 4JB1 engine, the injector pump will draw from the tank without assistance.

1988 Isuzu Trooper LS
2.8l Isuzu 4JB1-TC intercooled turbo diesel
www.dieseltrooper.blogspot.com