Catalinas for Coastal Command before the war

What American aircraft should Coastal Command have ordered in 1938 to avoid Air Ministry interference?

The Catalina, already in production since 1936. Coastal Command needed many flying boats, but the Air Ministry would still place the order.

The Catalina is the preferred American aircraft for a 1938 order. It had been in production since 1936, making it an established choice by the date in the question. The priority is obtaining flying boats in quantity because Coastal Command never had enough. The suggested route would still involve the Air Ministry: Coastal Command belonged to the Royal Air Force, so the ministry would place the order.