It can be done & has been done before. The Chinkara people don't offer 4WD on their jeepster though. If you want you can even retain the 3-spd...I have checked out one such MM540 myself and it moves pretty good though it tops out very soon.
Main things to look out for are matching the engine and gearbox. Your present final drive may be unsuitable for the new engine and may have to changed. Not a problem because there are many ratios available for Jeep diffs.
There's no need to go in for a header because you may lose some low-end in the process. For turbo conversion contact one Mr. Psycho
.