That is by far the best looking and probably most effective sunroof ever fitted to a Mini.
We have one on the R53 and it's great. Maybe if it gets written off/scrapped I will salvage it
I would imagine the easiest way to install it would be to chop it out with the roof and trim the section until it nearly fits in the Mini roof and then perfect it. You would undoubtedly need extra supports/bracing in the roof. You would also need to see how the centre of gravity has been affected.