When i did mine, it was fully stripped, it took 4 litres of white. That was the main one used, the black wasn't any where as much as its just the cab and bobtach, 1 litre would do for that. I got 1 litre mixed up for the rear door and wheels rims, still had heaps left over.
As for thinners/reducer, that depends on the paint you get, I'd suspect about half of the paint you get? so for 4 litres, you may want 2 but it really depends on your conditions. Reducer slows the paint drying time down and thins it out. I use a spray gun and pour in the paint and what i feel is about right for the reducer. Not the perfect way to do it, but it works great for me.
The hardest part you will have is over spray. You need to cover hoses and black parts when painting white, same with the black, it will be mostly prep work.
Good luck, and i hope you take pictures! I have some laying around here somewhere.