Hi Tony, welcome to MINI2 ....
This would certainly be one of those items that if not factory fitted surely would not be worth the hassle
Not only would you have to get the correct wiring, but you'd also need a new heater control panel with a button to activate the screen, plus then you'd need the screen itself.
I can't realistically see it as being worthwhile I'm afraid... I do have it fitted (as part of the vis pack) on my car though, and it's mightily effective).
Jon