I think Helen Stowell is in Shropshire. If you go to www.epauk.org they have an interactive map so that you can find an EP near you. All Equine Podiatrists registered with the EPAUK are required to be fully insured and to complete extensive CPD each year. The training course is 2 years long and extremely in depth.
I'd second both using the EPAUK website to find a qualified Podiatrist or a Farrier with an interest in barefoot trimming, as with all skilled things you're best bet is with a qualified professional