I use Newcastle Hardwood occasionally. They're usually very helpful and if they don't have what you want they can probably order it. I've only used them for small amounts of timber and they once let me raid their off cut bin for a small length I needed.
If you are after small quantities I might be able to help, I live near Hexham. I have some oak, elm and various other bits and bobs. Feel free to ring. 01434 230761.
Thanks for the advise. I am new to this forum and woodwork and the help available has been invaluable. I will give you a ring at some point. I live in Consett so your not very far away.