I asked a while back if there were any software-based DRB-II scanners which would run on a laptop, such as you can get for OBD, but there was nothing. It looks like the only option is to find a professional unit.
According to the DRB-III manual, it's designed to work with vehicles from 1994 onwards, but is hardware-capable of supporting older vehicles. I think that means that to use it with a 1993 ZJ you'd have to have the relevant plug-in firmware module. The biggest problem though, as you say, is the price.
If you just want to bleed the ABS system, you can also use the Thexton 133 or Ford t90p-50-ala. These aren't scan tools, they plug directly into the ABS system via the ABS computer connector and cycle the valves to flush any trapped air out of the system. Back in 2006 you could get a Thexton for under $60.