The 4D55 turbo diesel seemed to have the same or more power than the ford 4.0L V6 so it should be doable. No the KM148 does not match up to the Mitsu 3.0. These engines are being imported used from Japan. Don't know if all the accessories are attached. This diesel was "instant start", no waiting, but drew over 200 amps to the glow plugs. It had a 1200CCA battery under the bed.
Don't worry too much about finding a mechanic. They are available for VW, Audi, etc.
The Cherokee once had the 2.8 diesel from the Datsun.
If you could find one and add a turbo it should be even better.
Bob Shaw