If you want another recommendation in Sussex, Elliot Rowe at Rowebuck Sports Horses nr Uckfield (I think!) is good. He was highly recommended to me on here for a friend and she got an aboslutely lovely young warmblood from him and the service and trial time/facilities etc were really good.
My friend bought a really lovely mare from her 3 years ago and was so happy they went and bought another horse from her a year later, both horses are lovely