Go to www.dance afloat.co.uk.
Www.danceafloat.com provides dance hosts for Fred. Olsen Cruise Lines, www. seabreezeagency.com provides dance hosts for the Saga Shipping Company, and the only other British agency that I am aware of is www.2stepcompany.co.uk. I am not sure which cruise companies the latter provides for as I have not worked for them.
Both Fred.Olsen and Saga offer excellent cruise experiences but my personal favourite is Saga.
Danceafloat and Seabreeze are excellent agencies and are very similar in the way they are run. You will find that the experienced dance hosts are registered with 2 or more agencies and you will find that you can change from one cruise line to the other very easily to maximise your cruise experiences.