Upvote:3
I would imagine you'd find something in the main touristy area, like Noosa Heads/Noosa Junction. Also, Sunshine Plaza in Maroochydore would be a good bet, although it's a bit of a drive. It's one of the bigger shopping malls in the Sunshine Coast region, so it might have better competition re: exchange rates.
I've also heard that some banks, like Suncorp, will do foreigh currency exchange, but i can't vouch for the quality of their rates.