Vea sports also do custom gun work including lasering, anno work and are the only uk company to do splash annodising. Follow the link in my sig to talk to them and the guys name is Julien.
Kent also is a nice guy and does nice work.
If you need vector artwork drawing up to be laser engraved I should be able to help with the design side of things. The actual lasering on the other hand, not so much...