Great idea.
Sherrin Motorsport has been a popular choice up here in QLD lately. Chief instructor is Paul Stokell.
http://www.sherrinmotorsport.com.au/..._trackdays.php
No idea in Vic, but you could always contact Sherrin and see if they have anyone they recommend down there.
Personally I would just find a training course that suits your needs and budget and just book it yourself. Then let other club members know the details and how to book themselves. A lot easier than going to the trouble of organising a dedicated club day.
QLD club has done both club only driver training days and lately a few training days where they just jump onto an existing planned course.
Wazza(Our President) just completed one with Sherrin last weekend. So maybe he can chime in with his thoughts.