Downtown 42 ,
Checkout Loadmaster Ltd. in Port Clinton, Ohio. No relation to Loadmaster in Florida.
They build steel trailers using open channel. The bunks supports can be welded or adjustable. They did a trailer for my 32' sportfish Fountain. It's a 1996 and that year fountain had two hull step configurations for this model.
They got with Fountain and did the step correctly. Their finished product looks as goos as everything discussed here.
They'll do any custom work you want.
Also there close to Illinois.