Not clear to me why you want something denser than the Pelican-type stuff, but there are options. First, go to local upholstery supply and see what you can lay your hands on. The black foam like the Pelican stuff comes in various thicknesses, starting at maybe 1/8" or 1/4" and goes up to the thick stuff. Take a page from the old-school camera cases and build compartments from thin plywood or plastic sheet (get lexan or other 1/8" polycarbonate from a plastics wholesaler). Use something like 3M 77 spray adhesive to line the compartments with whatever foam thickness works for you. Or, you can go completely overboard and lay out your stuff in whatever space you are filling, wrap the stuff tightly in plastic shrink wrap or Saran Wrap and then foam everything into place with aerosol insulation foam from Home Depot. The foam will overflow the container, but don't touch it or mess with it until it cures. After cure, slice off the excess, pull your stuff out and unwrap it. then paint the foam with something like elastomeric house paint to seal everything and make it easy to hose out after trips. The foam-in-place is probably overkill, but it locks everything precisely in place and prevents any kind of movement. Used a lot for shipping fragile and/or expensive equipment.
