Which type of tradesman do we need?

[RenoRuby]

We are looking for advice on how to reconfigure our kitchen/diner/utility to let more light in and make the layout more practical (possibly knocking down walls, moving units and appliances around, installing French doors etc.) and where is best to install a downstairs toilet.
Who would be best to ask round- a plumber, kitchen fitter, builder?

I think a good building contractor should be able to advise on all those things. It's also worth getting in touch with the council to check if any work you plan is subject to building regs.

Architect