Hi Pito,
I apologize if you had already thought of this but if you can tolerate the network latency and your robot isn’t too sensitive to slightly “late” sensor data (but still accurately timestamped), you can always have a more powerful computer (ie laptop or desktop) run the more computationally heavy ROS nodes as secondary processors - no need to have these processors actually on the robot (which just sucks up more power and requires heavier duty motors). Just another architectural thought to help your students keep cost down while still being able to build their own full fledged ROS robot.
Happy to continue to hear your thoughts, and “discourse” (harhar!).
Cheers
Jack