you use 3/4" ply for the surface, and build the frame out of either 2"x4" timber or you can use scaffolding poles and brackets. Building a small woody out of 2x4s and ply is piss and reasonably cheap, Unfortunatley for you your uni's department of estates and buildings will probably insist on safety and building regulations being met in order for them to alow this and be on their insurance etc, which probably means getting legitimate professional builders in to do it, which then escalates the cost a lot. Presumably you alreayd have permission from your uni to do this, so they should be able to tell you what regs they insist on being met. There are loads of websites on the net telling you how to build a frame to attach the plywood to, you will often have to use common sense to unamericanize the descriptions though. use google.
