Forgot to mention.
In terms of reliable secondhand dealers, I've had a few bits and pieces from these guys before;
https://secure.ffordes.com/index.htm
Always very helpful, and when ordering online I've always received a personal email from one of the people at the shop. Shipping has always been lightening fast too.
Although I've never been to the shop as it's a bit far north, if I ever found myself there I would certainly drop in to them. They seem very knowledgeable and helpful, prices arent too bad, and they usually have quite a variety of secondhand gear, with a fast turnaround of listed stock too.
Hope his helps