A good farrier, they have been keeping horses sound without shoes since before 'barefoot' became a fashionable word and 'barefoot trimmers' popped up all over the place.
I use Oliver Mitchell (farrier) for my 3 barefooted. Think he covers Preston. He's done wonders with my Appaloosa with the rubbish feet, advising on diet etc as well as just trimming, and never advocated shoeing them even when I specifically asked if Appie would do better with them, and he has been very patient with her - she knocked him through a fence when I first got her.
I use karen Beaumont and I can't recommend her highly enough. My boy had a terrible crack in his foot that every farrier and trimmer said would never go...9 months of trimming from Karen and the crack has totally grown out. She is fabulous. I'm sure she covers your area. Feel free to pm me if you would like her details.