my bench is made of 3" x 8" redgum garden timber 'sleepers', took a while to season, but now its as stable as you could want. Initally i dowelled and glued, but as it dried it moved and split, so i drilled holes all the way through and bolted. (all-thread, with counterbores for nuts. )
the legs were 3×5 fence posts, but probably a bit lighter and bolted to floor/wall would be better.
Its as solid as anyone could want, i can hammer in the middle with virtually no bounce. The big drawback is it is a major effort to move, around 80Kg just for the top.
i have small chests of drawers underneath.
If money was less an object, then flatpack kitchen cupboards/drawers would be nice, with a 38mm benchtop, or a couple of layers of thinner board well screwed or glued together. 1" thick is a bit thin for hammering on. A nice smooth laminate on top would be nice, but then one hesitates to drill holes in it to bolt things down…
Of course, i suppose it all depends on what you plan to do on your bench…
– russ