Where to buy grapes in Melbourne

Hey y’all! My brothers and I are going to have our hand at making a wine this year and would love some advice.

What are the regions you’d look out for that will have excess grapes at an affordable cost?

I’d love fruit from Mornington but I’m sure that’s a bit of a pipe dream in terms of availability and price. I was thinking King Valley or Rutherglen maybe? Not fussed on variety and would rather look for good fruit.