I'd suggest that you check out
VEX Robotics education section. You want classroom kits and either the Autodesk or Carnegie-Mellon's Robotics Academy curriculum. Purchase some Plano Stow-n-Go boxes to put parts in to make them portable.
We do a similar thing for our mentor workshops, we just don't let the kits go home.
VEX robotics kits are used in a ton of schools, their market isn't the robot competition it's the schools. A nice side benefit is the VEX competitions. Lots and lots of "tech-ed" teachers use it, see the TSA info on their web site.
It's a good idea, keep us posted on how you make out!