I may be crazy, but if I were doing this, I'd fly out of ITM and get there by taking the Keihan train to Kadomashi, then changing to the Osaka Monorail. This is certainly not the fastest or easiest way to do it, but the two train rides are really cool: Keihan literally takes you through people's backyards in the suburbs, then the monorail takes you down an expressway median at altitude past the Osaka Expo Park. Also, if you fly JAL out of ITM, you might have an opportunity to upgrade with cash to domestic F, one of the most opulent hour-long flight experiences you'll ever enjoy...