Marine Refrogeration
Michel,I don't know if your compressor is large enough to handle a holding plate or not.  I suggest you contact the customer service department of Refrigeration Parts Solution at 1-800-720-3907.  I think your Adler Barbour is a 1/8th HP compressor and you will need at least a 14th HP Compressor to do what you want. The cost of a holding plate is about $230 plus you would need additional parts to make it work.  Their 14th HP system with water cooling runs about $1200 and you have to install it.  Good Luck.