Our district is reconsidering the design of its gifted program, looking at options including differentiation within integrated classrooms, pull-out models, and self-contained gifted classrooms. The current model is a mix of those (varying by grade), but there is a push toward more integrated classrooms, with the cited reasons being improved equity and access, reduced elitism, lower stress, better differentiation for all students, opportunities for age group peers to interact, and opportunities for students to work and interact with students of all abilities. Math detracking in San Francisco has been mentioned as one example to emulate.

I am looking for resources (preferably research) on models have been tried, and how effective they have been at meeting the needs of gifted students and the rest of the student population. As well as must-have characteristics within each of those models.

Some posts and other resources that I have found helpful so far are:
What A Child Doesn't Learn
A Nation Empowered (and A Nation Deceived)
NAGC Gifted Education Strategies