Hi,
As a start to answering the original question, I have dealt with working full time on the net since early 2000 and am based in the UK. An just getting my second company registered, so I think I have some input into the UK market.
Having said that there are plenty of people out there that dealmore with UK domains, but mt advice for quality ones is to market them directly. Having said that I do not know your level of experience in the buisness sector so I do not know how to taylor my response ( please feel free to contact me directly if you like ).
Personally in the UK I have found that directly marketing your domain to a prospective client is more efficient than most approaches, but as with anything in this trade it really does depend on the domain name and your ability to market it.
Despite what a lot of people will say this business is not an easy way to making cash

.... I wish it was.
I would be happy to help you out more but I would need more information about what you are trying to market. At this point I should point out that I would not be looking for any money, I would not disclose details or anything like that.
A lot of people in this business think of everyone else as competiton, I look at them as being the people that will shape the trade for the future .... The more we can teach in terms of professional business dealings then the better we all look, and we can rid ourselves of this image as money grabbers and un-professional idiots.
Anyway it is time to get off my high-horse

Let me know if I can be of any help.
Wishing you all the best.
Richard