The latest firmware for the 1200z allows you to change both track voltage and track amps so you should able to use this system with any scale, in theory that is.
The latest Massoth firmware is 2.40 but even if your unit has this listed i would download and upgrade the version from massoth website as there is a slight difference.
This firmware can be used on any 1200z unit be it new or old, mine was one of the first few over here in the UK and updates fine.
Goodluck mate as this system is very nice to use and love it but it's one hell of an outlay thats for sure.
Jason.