Which vehicle preparator ?

Hello

I have a Defender 130 300 TDi that I want to get modified to make it a safari vehicle for East Africa.
Typically I want to get a case fitted in the back with freezer, fridge, drawers, water tank, additional fuel tank, roof tent, etc...
So a fair number of things before shipping it to Mombasa.

Would any of you have a recommendation for a good and reliable vehicle preparator that he has tried in the UK and could really recommend please?

Thank you

I do my own, but a very good friend of mine used Foley specialist vehicles , not the cheapest but was very pleased with the end product HTSH usual disclaimers