Uncle Fester,
There are few places to try:-
1. Adventure Sports in Noosaville. Have good boards and will deliver. my pick.
2. SUP Noosa, on the river in Noosaville, have a variety of boards.
3. Noosa Stand Up Paddle also on the river at Noosaville, as above.
4. Beach Hire guy on main beach, not sure what he has.
Have fun.
ET.