Fast Eddy is definitely the man to go to, he’s very MX5 performance orintated and experienced, he did the suspension work on my Mk3.5 and also looks after my Mk1 track day car.
Michael Cleverly is excellent. He did a complete overhaul of the underside of my 2003 Nevada last year and it has really benefited from it. He is a little way from Norwich (about a 35/40 minute drive) but well worth the trip.