For the paint, I would recommend Edmundson's at Thruxton, I think the telephone number is: 01264 773200. You will get a first class job, they are normally really busy and there is a long wait, but in my opinion, it is well worth it!
For the interior, Patriot Aviation at Cranfield are the Bell dealers for UK and Eire, you could give them a try. Telephone number is:- 01234 752220.