Instead of adding a transport we could add a feature for a way of making the troops walk their lazy rear-ends to a base. We do all that flyin and get shot at and what not, all they do is run into a room and stand around in there untill it fills up, then they move else where on the base.(Bet you didn't know thats how captures work, did ya)
On a non-sarcastic note maybe add a faster transport beacause, speed is a defence. Examples are:
British Avro York, Carried comparable load to c-47 and fly at 290mph, entered service in 1944.Modified version of lancaster, which could ease modelling constraints.
C-46, Primary American transport in PTO. speed only slightly better at 269mph. Had a nice comfy pressurized cabin though.
C-54, small cargo space (7-15 passengers) 300mph
Transports really are towards the bottom of things we could use especially more allied ones, but I have not really seen too many axis transports that would be any better than the c-47.