You can also check out the official FTB wiki. It's not totally complete yet, but we do have an article for the Cargo Manager.
You can use all vanilla saplings. Jungle Saplings work, but they will grow the 9 block tall single block trunked ones, as opposed to the 30 block tall double block trunked ones.Anyone know which saplings you can't use in this? I'm thinking you probably can't use jungle saplings for a steve's carts tree farm or atleast not with my current setup