Thanks for the interest, once again.
I would differ slightly, in terms of "how to go about things". I'd probably use the following milestone markers to chart the progress of the build...
a) Sort out the frame, free it from all imperfections, damage, and the like.
b) Attach the axles/tubes.
c) Mount the wheels and tyres. Visually assess whether or not they "sit" right. At this point, extending/truncating the frame as per requirements is still fairly simple.
d) Mount the engine, transmission, transfer case. Affix the other parts of the drivetrain, and again, see how it "sits", before adding the shocks / springs.
e) Mount the shocks and adjust to the point where they're just about right (perhaps somewhat extended, rather than compressed...since it's still going to take on some more weight) before adding the tubing.
f) Fabricate the exo-skeleton around everything else. Where required, put in the floorpan. The space for the fuel tank. Where the seats will be anchored. Get the fabricator to build it around YOU; for it to be supremely comfortable, and fit your dimensions.
g) Add electricals, concurrently. Exhaust, cooling system, lights, recovery system, seats, protective harnesses, et al.
h) Strip to the bone, once again.
i) Powder coat / paint.