You're only allowed an International Dirvers Permit once in Japan. Can't get another one.
It's actually quite easy for you to get a Japanese license for you since you are Australian. Pretty much get some paperwork in order from your licensing facility in your home town, then submit it at the prefectural divers office.
As for getting Cappucinos, I don't know. They deal mostly with GT type cars. I.E. Skylines, Mark II/Chasers, RX7's, Silvia and 180SX, etc.
If you want a Cappucino, I can ask them, but I don't know for sure.