I build mine normaly like I build any work bench. If light weight 2x4's and 1/2 in plywood. If heavy duty 4x4's and 3/4 inch plywood. Locking casters on the bottom so I can rool it around. Lag bolts and 16p nails. The one in my garage was built in 1998 and has a vice at one end, grinder/wire brush at the other and a barrel vise in on the side and is. Sheet opf ply wood cut in half and boxed top and bottom and X braced on the sides. I have had a variety of engines, transmissions and axles on it and it is as sound today as it was when I built it. I scale this up and down for reloading gear and any other projects. Nothing as complicated as a work bench for wood working with built in clamps and built in wood vises or the like. Just like squares, A frame, X brace.
If it is just electronics you could lighten things up a lot, finish it with trim, do a poured epoxy surface, stain it or paint it or even veneer. You could reuse bowling alley flooring, laminet flooring, high school particle board lunch room tables, butter block counter top etc.....
My shooting rest was made from chunk of high school basket ball court that was thrown out due to water damage it is super nice and heavy and was free. I took it from a dumpster.
If it was only ever going tobe used for modern electronics no 1950's commerical gear repurposed you could make it super light weight. think 2x2's, 1/4 inch plywood, wood trim, and pour an epoxy top. Toss down some neoprene or silicone matts. Drill pilot holes and use either nails or screws counter sink and pill with puddy then paint.
You could go the opposite direction and weld up a still frame and have a local powder coat it and then do a Walnut slab if that is more your style.
You could do one up like a Sunburst Guitar or you could do a British Hunting Rifle and use Alkanet Root and Linseed oil.
What do you like? What are you passionate about? I mean heck if you are some weirdo into brutalist archetecture you could do poured concrete counter top on simple wooden structure. I have some benches which where just old steel case desks slide together!