I really lucked out when we bought our house. I worked at TRW at the time and they had a sale of some work benches from the electrical shop and various other shops on campus. I bought one out of the surplus store for $40. It has a reversible masonite top on it that is @1.5" thick, two sets of full depth drawers (36") and is 8' long. My garage had a door on 4x4's for a work bench when we bought it. My brother loaned me his El Camino to haul it home. He wouldn't drive it as it was so loaded down it looked like it'd flip over backwards from the weight of the bench.
It hasn't moved in the 35+ yrs we've been here.
The back and top shelf came with it, along with the power strip too.

As you can see, I'm a clean freak when it comes to my bench.