we are looking to replace also
as our control board and compressor blew......the plate systems seam to be the "best" way to go, as they drain less electricity from the battery bank and are driven off the engine, This syetem basicly "cools" the plate (that contains a gel ike the freezer blocks you pack in a cooler) in the box and that slowly and continually radiates coolness in the box. ,,but Im looking at cost also,,,so we might go with the direct replacement ,The main drawback with this system is that it recycles 50% of the time,,,so it does have an effect on your battery bank and will have to be constantly monitored. The best price I have found is on the attached link.....if anyone has found it less expensive please let me know.