These guys are based in Pickering and do a lot of heritage stuff. Really good service as well and will happily advise you on what suits what growing conditions etc
www.rvroger.co.uk
I'm no expert but I've always been told to buy bare root stock as pot grown can be less hardy due to being drip fed and watered it's whole life (bare root is a bit tougher!)
I've also been told to always buy MM106 root stock and then train / prune into a smaller tree if required rather than buying a dwarfing variety as they tend to have a shorter life span so avoid M27 (dwarf) rootstock.
Good luck
