Time, Money and a Donor Truck... I would think buying a wrecked D-max would be your best option to do the Swap. 2WD or 4WD?
A 2WD would be way easier.
The guys at ATS Diesel are putting a Duramax/Allison and AAM 9.25 front axle into their '99 F350 called Great White. Call them up and see if you can find out what is involved in the swap from them.
Scott