i just checked the harbor freight catalog - no 60,000psi compressors.
i have a design for a waterjet in my head now. it involves a smallish AC motor driving a hydralic pump, driving the BIGGEST, most unholly used pneumatic\hydralic piston you can find\support in your facility. this can be driving water in a high-pressure steel vessel that feeds into a small nozzle. i dunno.
i have never seen a waterjet cutter in action. you plan on using this thing to cut thick steel or something like that?