Dont be ridiculous...
Not in Hobart, but according to RACT, a competing oil company is coming to Tassie and they are bringing 98RON with them. So hopefully, maybe August, probably Xmas.
As for the other, I'm sure one of the guys on here will point ya in the right direction, I'm too noob to tell ya....
Search turn up a couple....
Octane boost
Greebo