Which material for main structure of Virtual Reality Simulator?

Hi everyone!

I want to make my own Virtual Reality simulator that would look like this one on this video and picture: https://youtu.be/cwknOvHVNMA

It consists basically in two boards attached together through a springs suspension system. I believe the upper board will have to be strong enough to resist the forces of the users on the handlebar (specially the joints handlebar-upperboard); while the lower board will have to be heavy and stiff enough to avoid a potential “roll”.

Could you please advise on which composite material would be best suited for the task?

NOTE: I believe they are using composite materials due to the soft fillet on the edges which discards wood, metal or plywood.

Thanks!