This is a good source of information.
http://www.sfu.ca/~mmh/BritishX.htm
I think Omega WWWs can be pricey. For the money they go for, I'd stretch to an Omega 53 if you really wanted an Omega.
Other WWW brands like Record are reasonable if you are just starting out.
Check out Sales Corner on the forum, or PX on http://www.broadarrow.net/
Regards