Just gauging if there is any interest. I am in the process of making one for myself from 316 grade stainless steel.
The flanges will be 12mm thick and the tubes will have a wall thickness of 2.7mm. I don't have any pricing as yet, but with any sort of fabrication, making one item is just as expensive as making five. I will be making mine with external wastgate (Tial 44mm), but they can be made with no wastgate provision if preferred.
The manifold is being made to suite my car, a 1980 Ford Escort fitted with a 2 litre zetec engine with raceline water manifold. (The retro ford water manifold will also fit, as I have access to one to make sure it fits too).
Just reply via PM or to this thread if you are interested, as I get closer to getting mine made, I can give you some idea of cost.