I've grown up waterskiing and snow skiing, so yep, that's where the name comes from.
ISO mount is what some manufacturers use to secure the headunit to the car, and it entails a set of brackets that secure to the sides of the headunit and then bolt directly to the dash. Typically that is performed before the trim bezel of the dash pops on which covers all of the mounting hardware and sets the reveal of the headunit.
As long as the opening is double DIN sized and the aftermarket headunit support DIN sleeve mounting (which the Z1 does) you can use that method to install. I know Pioneer offers a double DIN sleeve kit but I don't know the part number and last time I checked it was back ordered. A DIN sleeve from any manufacturer will work though (Kenwood, Alpine, etc.). The sleeve slides into the dash, then you bend out some tabs to hold it in place, and the headunit slides into the sleeve and locks in place.