How to set up a E.P.R....Evaporator pressure regulator

Hey guys, I been working on a lot of pleasure boats/yachts recently and am looking for a better idea how to set up the E.P.R and also the Superheat on the Freezer. Il give you the basic explantaion of the System: Its a Clutch Driven Compressor off the main Engine, sea Water cooled Condenser that will be Cooling 2 fridges at around 3-5.c and a Freezer -18.c all 3 are Brine insulated and run on R406a. Also just before the fridge Lines join into the freezer suction (making it a common Suction line) theres a check valve for the freezer.

Basically am looking for some suggestions on this, of what type of pressures in the evaporators for the fridges would I be looking for and also setting the superheat up on the Freezer would be done best AFTER setting up the 2 E.P.R's

regards Nzpomme