Find a wrecked 2wd xk with a d44 rear and use that. Infinitely more gearing/carrier options.
Tcase and trans are fine. Computer is fine (for qti and qtii)
Yes it will be a very expensive build.... youre not gonna SAS a commander for cheap. Done smart, I think it would be under 10k though.
Consider superlift+rcv axles+gears = $6ish... and thats theoretical since we can't regear... so its not completely unreasonable.