For photo polymer printing plates, try Boxcar press. The KM73 plates are what I use for plastic photogravure. They require high actinic light in exposure, for which I use a facial tanning lamp, set up at 4" above the plate glass that holds my photo positive to the emulsion. I researched sourcing of the emulsion a bit, but the plates were actually what I wanted, so I gave up the search rather early and found little that would help.