I have been through a similar exercise lately, although a little bit more drastic.
I kept only the Frigiking evaporator and replaced everything else. New Sanden 134a compressor, new condenser, managed to squeeze an electric fan between the grille and the new condenser, new filter dryer, new refrigerant hoses and a pressure switch for protection.
My mechanic had to make an adapter in a machine shop to mount the Sanden unit but the result is an excellent setup. The compressor comes on and off very smoothly (vast difference from the old York unit) and I have connected the wire energising the compressor clutch via a relay to the constant speed solenoid on the intake manifold and adjusted the solenoid to provide a solid 700rpm in gear with the compressor on. Beautiful.....
I can post some picture online if any one is interested to see the installation...
