Question: who can make me an exhaust manifold to hold my new turbo onto my engine? I've read the Practical Performance Car guide to making your own and it looks a) difficult

hard work and c) like a lot of welding. My welding is passable but rather pigeon-like and probably not suitable for a high-vibration application like this - I'll stick to welding spotlight mounts etc - and sorting the gas, oil and water in/out piping.
I'm also conscious that there's a certain art to making exhausts, although less so for one that's subsequently blocked by a turbine, so ideally the recommended supplier would also have some experience in this, and some maths to satisfy the engineer in me.
Any pointers, ideally in the SW?
Cheers, John