The best medical outfit for all things male enhancement in London (UK) would be
Androfill UK , although as of now I know they're mainly focused on girth enhancement (by way of injectable dermal fillers).
They do offer a suite of other services, perhaps
@Androfill
can chime in on whether length and/or circumcision services are available.
Dr. Greta has been doing great work and I'd recommend at least a consultation if you are in London, you should be able to access it easily via
the tube.