ATA shouldn't have any problems introducing the 767 into their fleet if they decide to add it to their fleet. They already have the 757 in their fleet, which means that pilot training is minimal, only differences training. They also already have an approved ETOPS program. The only real training would be in maintenance.
As for the 717, they will need a lot more aircraft than what HA
has. They would still have to order more from Boeing. Plus you're going to have a split fleet anyway, unless you constantly ferry aircraft between Hawaii and the mainland.
isn't doing as bad as you think. Plus, Boeing has told the bidders that who ever is sucessful in bidding for HA
will get reduced lease terms.