I'm building a workbench in my RV and am researching the best wood top for my bench. Weight is an important consideration as I'll be putting it on a fold-up hinge but more important is something that is the right strength and grain for everything from cutting to punching holes to hammering. The underside of the bench will be sitting on top of a couch (see picture) for sound dampening and to diffuse the impact of punching and riveting etc.
Any thoughts on the best wood (light and strong) for this project? I'm expecting it to be about 4ft long x 2.5ft deep.

Don't breathe the dust if you are cutting or sanding it, as it is carcinogenic. Same applies if you burning any waste MDF.