Hi Craig, congrats on your certification! 
I’m not sure there is an active B Local Melbourne yet (if not maybe you should get involved 
).
There are too many Melb-based B Corps to mention but one of my faves is Harvey (@simon.smallchua) and of course Who Gives A Crap. The new Events & Engagement Manager @LucindaW might be able to recommend some local B Corps who could come to your event.
And Assembly our first big gathering in years is taking place in Feb, if you & the team can make it, it will be epic!
https://www.assembly2024.com/
Congrats again and welcome to the community! I head up Quiip which is an online community/social media company so I can’t help myself but act like a CM in here!