I chartered a Ben 343 several times. The "self contained" 12k btu unit was placed under a port setee, with ducts into the main salon, forward & aft berths. I would definitely avoid a single discharge configuration. I had a Hunter 33.5 that had a self contained unit with single discharge in the main salon only. The berth areas were always too hot in summer & too cold in winter. Might want to investigate why Ben installed in the location that they did----probably the optimal location for efficiency. Call Ben or cruisair for professional advice. Many yards will install in a location that is easy for them; not necessarily the optimal area. That's what happened to me.
My current boat, Ben 343, has a cruisair split system (compressor & 2 air handlers)that was installed by a marine air conditioning firm by the previous owner. Nice set up; however, definitely overdone. Will no doubt be expensive to repair in future.