Many years ago, I decided to design a work bench. My criteria was:
-about 2 feet by 8 feet work top surface
-bolted construction (so it could be easily moved from house to house, over time)
-screwed to studs in the wall to make it a rigid structure
This is the design I came up with.........
The work surface is 23x96 inches. I take a 1/2" thick sheet of plywood, then rip it to make a double level top.......with each piece being 23x96 inches. The legs are double 2x4's, which are bolted to the work surface frame. I usually screw the back of the bench to the wall studs, in 2 different places. This bench can be dis-assembled or re-assembled in less than 1 hour. My original work bench moved from Illinois, to South Carolina, to Georgia, and back to Illinois..........so the portability concept has been pretty well proven!
If one wants a different work top size, the design can be easily modified as required.
Back in the 1980's when I built the first bench, there was no personal computers yet to use Sketchup on. A couple of years ago I entered my design into Sketchup, because my son wanted a modified version of this design.