If money was no object & I'd buy a New Iveco Daily 4X4 and put the engine gearbox & running gear with its locking front & rear diffs into the Series 3 .

Iveco Daily 4x4 goes on sale | carsguide.com.au

Infact , to heck with the Series 3 I'd like that running gear in my Defender

Not to worry about Parochialism because the daily running gear was used in the Iveco Massif which is a rebadged Santana Series 3 LandRover