CNC waterjet cutter....pump and nozzles available???

I have a friend that wants to a 48"x48" or so working area abrasive
waterjet cutter. Has anyone built thier own? If so, what was done for
the pump and the nozzle?

The use would be for sheetmetal up to ~3/8" thick max, would we be
better off building a plasma cutter table? Accuracy in the .005
to .010 would be nice...is that asking too much??

thanks,

Mike