If i were in your shoes and money is not an issue, I'll jump immediately sa patrol engine (TD42) and tranny-tranfer case...
If money is an issue...stick to your stock 4DR5...modify it (if possible) to accomodate a turbo and intercooler, match the gearing to your needs and tire size na lang.
Sir if I may ask how much would it totally cost if I bought a TD42 and a tranny transfer case? and in terms of fuel economy how would you rate it? thanks in advance