What basic grammar and usage handbook would you recommend for teaching college level English composition?

I think you should check out Writing from A to Z by Charles T. Brusaw. It takes a different approach to formatting by organizing itself like an encyclopedia, concepts are listed alphabetically for easy reference. It also contains comprehensive sections on citation, research, and composition. It's relatively small (505 pages but it is not full sized). It isn't exactly what you've described but it's worth a look. As a student, this is the best book I have ever owned and still use for all of my writing.