ive looked at the pics of yours and the one precision plasma has. they both look the same and the pics of the PP z axis is set on v rails. im only asking because i would like to upgrade to a better zaxis.
It is possible to use a different Z axis with the system. Since is it already installed you could theoretically put some support wheels between the gear rack and the edge of the support tube to ride down the flat area of the aluminum. These machines are not setup for routing out of the box and were never intended to be sold as a router/plasma because you cannot have the best of both worlds. You can have a router that has plenty of power but not alot of speed or you can have a plasma that has speed. Once you add cutting forces to the system alot of things change. There are some HD systems that use similar V rail for the Z/Y axis assembly however they are mounted to the long rail completely different and if you wanted to go that route it would be a totally different system with a different spacing on the table frame. Those start at $5400 for a gantry kit minus electronics.