Re full-size rigs, I'm experimenting with using the SafeJack pads and accessories on a Hummer H1 scissors jack. The SafeJack accessories are designed to fit over a 1-1/4" diameter bottle jack post and the H1 scissors jack has a 1-1/8" post on top to engage the H1 control arms (my rig is a Dodge 2500). I measured the outside of the H1 jack post and the inside of the SafeJack pad cups and both are within a thousandth or so of posted dimensions. So I'm planning to get some short pieces of steel or aluminum tubing with wall thickness of .060" or .062" and either slip them over the jack post or inside the cups on the SafeJack bits. Should be a friction fit, but I can add a dab of epoxy if necessary. I discussed this plan with Bogert before I ordered the SafeJack stuff and they think it will work safely (Bogert also makes hydraulic jacks for the uparmored Hummers, so they are familiar with the scissors jack). Their website specifies 1/2" minimum engagement on the bottle jack post and I'll have 1" on the H1 jack, so should be good to go, just need to find short pieces of the right tubing. I ordered the SafeJack frame cradle, axle cradle and flat pad. Will still carry my Hi-Lift but the H1 jack will work where the Hi-Lift is dicey, and the H1 jack has a big steel skid welded to the bottom for the sand I'm usually in. I had an ARB Bushranger inflatable jack explode on me and drop the truck suddenly a few years ago, so looking at the H1 jack as a safer substitute. The H1 jacks are available on eBay as NOS or new Chinese manufacture at a wide range of prices.
Oh yeah, forgot to mention that the 20-ton stuff from Bogert won't fit the H1 jack because their cups are way too big. My Bogert stuff is all 6-ton, the truck is about 8500# fully loaded and I think the jack itself is rated for 8000#.