I believe she's more of a speaker than consultant but I've heard her speak about cluster grouping and gifted programming and she seemed to get it.
- Dr Dina Brulles http://www.nagc.org/bio/dina-brulles

I've also read this book -
http://www.amazon.ca/TEACHING-GIFTED-KIDS-REGULAR-CLASSROOM/dp/1575420899

Haven't seen anything in real life even remotely approaching what the book talks about but maybe somewhere there are teachers than can do this stuff....