I'd rather have the Short Sutherland than the PBY for the only reason that the Short Sutherland would be more survivable in a MA environment than the PBY-5/5A due to its greater number of defensive guns and sturdier construction.
The H8K Model 12 "Emily" would also be cool to see added to the game, with its defensive armament (5x 20mm cannons and 5x .303 mg) and bomb load (4k bombs or 2x torpedoes) it would see use in the MA. However, the H8K only saw service in limited numbers, with only 167 produced and the Model 12 being the most produced version (112).
In addition to the "Rufe" (A6M2-N) for port defense, it would be nice to also have the N1K1 "Rex" float plane as the 2nd plane for port defense. However, like the H8K Model 12, the Rex was only produced in small numbers (100) and saw limited action in the later part of the island campaigns before being recalled to the Japanese homeland to be used as part of the aerial defense against increased US bombing.