I would suggest David Harvie Austin (trained under Hal huggins) or David Cowan (who I think uses all safeties and diamondlite, but you might want to call and confirm that). Both are in London (I believe both are close to Euston Station).

These are the only two I found that used safeties and diamondlite, so I can't really recommend others. There is the Essaway dentist Dawn was talking about who uses a machine, but he doesn't use diamondlite and I gather insists on sedation (I'm sure she can tell you more).