Don't forget that P-38's are somewhat popular in the MA.
Also, P-39's and P-40's get lots of use in events - so there's lots of room for a variety of schemes there.
The new SBD will need some good coverage as well. USN, USMC, U.S. Army, and RNZAF all used them extensively.
If you feel like branching out to fill needs for events, we can use some more Stukas and He-111's before August's Battle of Britain 12 hour scenario.