Some friends of ours have used a company called Millpond. Googling today I also found Child Sleep Solutions. For around £200 they give you support in a tailored plan to help your child sleep and support over the phone for a few weeks.
Our ds, usually a good sleeper, has been coming into our room several times a night for over a month now. We've tried most things we can think of and asked for advice, but getting no where. Just wondering it anyone has had good experience of these kind of services and if it would be worth the money!