Composite board has a thin aluminium skin with a plastic centre. OK it's a lot more expensive than say far eastern ply but the whole thing would be lighter & easier to move about, it's already powder coated so no need to paint & comes in about 6 different colours plus it's pretty easy to cut so your woodworking guy could still manufacture it for you. Normal woodworking tools will be ok as long as any saws are fine toothed, for small jobs I use one of those throw away laminate saws that joiners use & the V groove I do with a normal hand help router.
Not the cheapest way to do it but would look good & last for years.