Self install is no problem
I have a 2000 model (MKII) Catalina 400 and installed A/C myself a couple of years ago. I don't know if your cabin layout is the same as the newer but I can certainly share information with you. I basically called up the Florida plant and was able to talk to the company that does the factory A/C installs for Catalina. I bought the units/parts from them and they told me how to install everything the way they did. It was a fun project and probably took the better part of a 30 to 40 hours (I'm slow) to finish. Basically, a 16K unit (MarineAir Vector compact--this is a heat pump and can heat fairly well in the winter as long as the water temp is above 40) goes underneath the V-berth on a shelf built against the hull on the starboard side; it supplies the V-berth, forward head, and main cabin. A 7K unit goes in the aft cabin port hanging locker on a shelf and supplies the aft cabin and aft head. You need two thru-hulls for intake (I shared the head intakes) and the discharge lines are T'ed into each sink drain. During summers in south Texas, the boat is very cool dockside and if at anchor we run the aft unit off the inverter on "humidity mode" after cooling down while on the generator (we have a 1000 ah bank and humidity mode only uses about 40amp/hrs every four hours and keeps it reasonably cool from 10pm to 7pm when we get up.
