Scott,
With the hopeful popularity of the Silver Meteor, I would think a continued "Southern" swing would be appropriate. I would like to see the blunt end obs already created modified for the ACL, the Pullman sleepers offered with Southern or ACL lettering (especially the purple/silver versions) and maybe another run of the 54 foot express reefers.
Yes, many of your products are out of my price range, but I do try to pick up some extra cars here and there from you.
As for steam, here are my suggestions:
ACL R-1 (also suitable for RF&P)
ACL K-15s 4-6-0 (suitable for ACL, Rockingham RR, East Carolina RR & V&CS)
ACL P-5a Pacifics
Southern PS-4 1380 (Only streamlined steam locomotive on Southern)