Fiona, I don't get away with the sort of stuff I wore in my twenties either (none of it fits me for a start )

I don't have an answer for you on stylists - but one of my favourite clothes labels has their shop in Northcote, so is probably not far from you. They have a website, google manque and you'll see what sort of stuff they do. Lots of sophisticated but a bit edgy/arty stuff that is designed for women, not girls. They also stock a lot of accessories / jewellery from local designers. You could also google dogstar, they are a fantastic label too.

One thing I've found is that the haircut absolutely makes an edgy look, and colour is a really important component to that. If I don't colour my hair, it doesn't matter how funky the cut is, because I naturally have fairish/auburny/mousy brown hair that doesn't lend itself well to edgy and cool. Looks great if I'm going for an earthy and natural look, but edgy needs to be striking and bold to work well. It can still work within your natural colour range, it doesn't need to be OTT or garish, but a good colourist will complement your skin tones whilst bringing out the cut.

Good luck - I reckon it would be fun going to see a stylist. Can you ask before you make the appointment to see a portfolio - see what sort of style they specialise in and whether it is in the same ballpark to what you would be comfortable with?