That's why I say PBY. While she's not REALLY a troop ship, she WAS used as a supply plane (PBYs were CRITICAL to Guadalcanal as one of the few reliable means of getting supplies through). As the PBY can also take off from both water AND land that further increases her flexibility (takeoffs from airfields AND ports). Also carried guns for self-defense so would be less vulnerable, and some variants were retrofit to carry torpedoes and bombs.
That, and she'd be useful for Midway types of scenarios, requiring someone to actually FIND the enemy's flattops.
