Hmm... not sure of anyone that you could contact directly - except maybe me...

There are quite a few guys around, but they tend to have their own lives...
The locker thing is a good idea until the seabreezes hit - at which point, Elwood is not so good to sail from. Until then, it is a good beach for the N/NW, W, SW winds that Melbourne gets in Spring; the seabreeze is S/SE, making Elwood offshore (aka not good for broken bits); the N/NE direction is a bit shadowed, but you can drag you gear up the beach 1km to a better spot (Port Ormond), but again is offshore.
If you can find someone/somewhere to store your gear, St Kilda beach is the place to go for the S/SE seabreeze. eg: I store a mate's gear in my van; I just ping him when I'm at the beach - its then up to him whether can make it down for a sail.
I'm 73kg, so use an 85l JP freewave with 4.5 (+25kn) to 7m (~12kn), with corresponding fins. My most common used sail is about 6m +/- 1m, although Spring-time in Melbourne can easily be 4.0 weather.
Depending on your skill level, you might find 100l is a little big for your weight -> the Bay gets a little choppy when the wind gets up (from about 17kn), the 100l may just be too flighty.