Ok, let me speak on this one. First you would have to locate an area where the thru hull seacock would fit and do not even consider thru the water ballast tank area. Second, you would have to figure where the compressor would go allowing a 3 inch minimum area of clearance on top, sides and back of unit. Make sure you have the unit next to where you can cut out for the return air grill. Then you would have to run shore power wiring in order to operate the AC. Since you do not have a bilge area , then the condensator you can purchase from Mermaid would work.
However, if you are sqeamish on drilling the holes, fiberglassing, placement of the compressor, then there is the cost of the AC unit itself if purchasing form Mermaid. I would suggest making a shelf type companion way door to place an inexpensive window unit on for air conditioning.
As for a generator, I would recommend the Honda 2000 but I think that costs in the area of $800 to $1,000.
As for the 260, more folks tend to stay on that boat more and I perfected the install on Mermaid units on that boats
crazy dave condon