No personal experience, but Nicola Watson has been highly recommended by lots of other Forumites. Try searching her name on the Forum to read recommendations. She works one-on-one with parents to support problems related to sleep and bed time routines.
Maybe if your brother is able to get a handle on the bedtime battles, things will improve from the ground up for his little one?
Nicola's website is here: [www.childsleepsolutions.co.uk