School Auditorium Podium/Lectern

My woodworking classes have been asked by school administration to build a podium for the new middle school that the district where I work is opening for next school year. I would like to know if there are any ideas besides locking casters for a wheel system that can lock up for use and lock down for transport. The front wheels (audience side) will be not have to move, it is just the back casters/wheels (speaker side) that would need to lock or raise up when in use.

I am looking for more than just a solution that works in a shop. However I can maybe adapt an idea too. I just need somewhere to start.

Thanks for the input. I will be posting pics and updates as the students progress on the project.