A very quick Google search brought up
these agents and I'm sure there are more.
As for self-publishing (sometimes called 'vanity publishing') there are many people offering this service - I seem to remember the small ads at the back of
Private Eye used to carry some, and the TLS must have some advertisers.
But in these internet-enabled age when every spotty 14-year old has a blog for her/his poetry, this might be the easiest and cheapest way of geting your stuff out there.... tasters or examples of your work on line; make sure you put in the widest possible number/type of search words etc. Just a thought.