Rostock,
To be a dispatcher in the UK u don't need a dispatcher license. Your best bet is through a handling agent. You shouldn't expect anymore than about £16k for it though, and that's only if you get a full time job. The only airlines I know hiring dispatchers directly is Jet 2, the rest is through ground handlers. Your not officially a dispatcher either, it's a load controller or a Turnaround Co-ordinater. Depending upon who you handle will depend upon Weither you will be required to do manual loadsheets or not. Give it a go and see, it's definitely a stepping stone in the industry and something to use as experience when applying for a f/o job and in today's climate any other experience in the industry is a bonus.
You have Servisair, Swissport and Menzies who are the big ground handlers. Swissport were hiring full time positions to operate the virgin domestic operation at LHR.
Hope this helps