I have fabricated a prototype base for my hi-lift. It is made from structural channel steel, the jack can be rotated 90 in the base. The base measures 8"X8". I also have talked to a local fabrictor that will make these for me so the welding will be prettier than mine. You will have to provide your own 1/2" pin. I can sell these for $70.00 plus shipping. If you want one send me a PM.

The photos show it being used to lift the front of my cummins powered Dodge Ram:

 

here's the story about the fabricator:

It's a small one man shop, he doesn't have time or want to be involved in marketing this. He is the only heavy industry in the area of mostly retired folks. His father who started the business died a couple of years ago and he is trying to stay in business, I'm just trying to help him keep his shop.

The name of the place is Smelter City, located in Cottonwood, AZ. He has no web site .