The TD5 has been fitted a handful of times into older vehicles, basically you would want a TD5 Defender or Discovery so you can get all the things you need, but your going to need the ECU all the associated wiring, throttle pedal, plumbing so on and so forth.
There is a guy who got a TD5 to run relatively stand alone by getting an after market ECU, this took all the sensor feeds from the engine and fed back only what the engine needed to run in a simple box - I think it was about £3500 though.
If it could be done neatly, in a well engineered manner I would consider it, but to be honest if I was going to go to all the trouble I would fit the TDV6 which has been done using a Simtek ECU.