At a machine shop auction several years ago I bought a whole pallet of various threaded rods with nuts and washers in 1/2", 3/4", 1", 1-1/2" and two inch diameters in lengths from 24 inches to 48 inches. I have a HF mini-mill that makes a good platform on which to mount lumber up to 8" x8" for drilling fairl;y precise holes. Depending on the purpose of the bench I am making I use either 4" x4", 6" x6", or 8" x8" corner posts in the height that I desire for the bench. I drill holes of the appropriate diameter to put the threaded rod through the corner posts and then thread the rods through the two by fours or two by sixes that I am using as the tops of the benches. I use appropriately sized bolts to brace the sides and corners with 2" x 4"s or 2" x 6"s. I have a motorcycle jack that can lift up to 1500 pounds and I use it to lift the benches and move them from the storage side of the garage to the work area as I need them. When the car and motorcycle are both parked outside I can use almost all of the floor space to set up the benches that I am using on current projects. When I am finished I use the motorcycle jack to move everything out of the way to allow parking for the cycle and car.
If I ever have to move to another shop I can disassemble everything in a few hours and have it ready to be loaded and unloaded in the box of my pickup truck.
I have back problems so I do most of my work from a wheelchair and since I cannot lift much weight anymore this allows me to move some really heavy stuff around my work area. Here is a list of various tools I have mounted on these portable benches.
Harbor Freight mini-mill Harbor Freigh 7 x 10 mini-lathe Craftsmen Drill Press Ryobi Wood Lathe. A Ryobi table saw. A Ryobi Router A 24' Scroll Saw Two carpenters tables with various vises built in. 48 inches by 24 inches. A 6" x4" Metal Bandsaw Two castor mounted boxes for secure storage of various power tools and odds & ends
It ain't pretty but it allows me to spend time in the shop instead of on the couch.