I made contact with Coast2coast based on a post on PH this morning and input my spec.
I then managed to get a guaranteed cost some £4000 cheaper than my dealer is offering from a BMW dealer oop north (and that was for a 7 seat rather than 5 seat) so I did what any man would do and did some man maths and added:
Pano roof
Front comfort seats
I'm very happy and think it's a very nice spec'd car now which I'm happy with

And I'm still over a bag of sand better off

As a matter of interest it would appear I've managed a discount of 10% plus BMW contribution, so quite a lot off list and circa £14000
I have a demo M50d for a long weekend shortly and will place my order after that. I suspect my current dealer will lose the business which is a shame but shit happens as they say.