Ditto what Scott said. When I was looking into buying a sawmill (thankfully I came to my senses ,though), I only found 5 manufactures for smaller circular milles (Peterson, Lucas, Meadows, and the other 2 I cant remember).
There are quite a lot of small old circ mills around. I never considered those, because they are IMHO exceedingly dangerous, need a lot of power, take up too much space, etc.
Main problem I found with those older mills is safety, large engine requirement, need at least 2 people to operate, quality of cut is marginal at best. It is pretty difficult to make and keep a 48" dia blade flat and running true.
My neighbor has one, it is an old Frick running of a 170hp cummings with flat belts. When cutting, the operator stands right behind a 48" sawblade...one slip and you are history. Also, he has hit a an embedded rock/nail, etc on occasion: The insert teeth of the blade fly off in all direction like shrapnell. The tin roof over the operator stand has small holes in it!
If you hit anything with a bandsaw, it may damage the band , but wouldn't hurt the operator.
Anyway, just my two cents
Bernhard