We were on the Ask An Expert feature at the Grand Designs LIVE exhibition last week at London Excel and met a supplier called TATA Steel. They sell a really neat and simple Standing Seam Roofing system in many colours that look identical to a zinc standing seam roof but will last up to 40 years and clicks in to place. Link here for images:
https://www.tatasteelconstruction.com/e ... rban-Seam®
If you contact Amanda.firstname.lastname@example.org
(07817557753) she will be able to recommend an installer.
Unfortunately I don't know a roofer that would be able to come in for this specific task but if I think of one ill let you know.