I think the US purchases should be as follows:
US1
2 aircraft carriers in Western US and 2 fighters in Central US (all to meet up on Hawaii on US2) (land the 2 Hawaii fighters on one of the carriers)
US2
2 aircraft carriers in Eastern US and 2 fighters in Central US (all to meet up in sz 101 on US3) (also land tac bomber on 1 carrier)
Note: if Japan has declared war on J1, use your extra IPC’s to build transports
US3
6 destroyers to go in sz 101.
Note: if Japan has declared war on J2, use your extra IPC’s to build transports
US4 and on:
all inf to go in as many trn as possible all destined for Europe and also destroyers to replace any destroyers lost in case Germany is using the Dark Skies strategy.