belt driven compressor replacement

[Mel]

I have a Blissfield compressor driven by a 12v 3/4 hp motor. It is connected to 2 holding plates. 1 in fridge and 1 in freezer. It is set up so that if the fridge comes on it also cools the freezer but the solenoid keeps the fridge from cooling when the freezer comes on. Can I replace this with a bd80 and use solenoids so only 1 plate is cooled at a time? the fridge is about 6 cu feet and freezer is about 3 cu feet. Would a Carel thermostat be able to control both or would I need 2? There are TXV's in both so how would I know how much charge to put in? I would like to set the system up like the Adler barbour super cold machine. To do this would I need to run through the water condenser or air condenser first? Can I possibly use my existing accumulator?