You can build a big desk that is more than strong enough for you to stand on using nothing but basic pine from the likes of home depot and some screws or glue.

I actually just built one that’s 5 feet long and am assembling another that’s 7 feet. They will fit together to make a big L-shaped desk for a couple PCs and some other stuff. I use 3/4" plywood for the top surface.

I’m making a 3-foot long one too that’s going to be a stand for a 55 gallon aquarium. That’s about 450lbs / 200kg if completely filled.