Easy peasy:
For capital growth: Any Zone 1 suburb south of the yarra, and pretty much anything along the beach, south of the yarra. Stay clear of multi unit developments where you are buying less that 30% land content for your hard earned $. Depends on what you pay for the property. Maybe try and buy near a private school.
For rental yield: Depends on what you pay for the property.
May not be easy though, but you cant prove I'm not lying.
All comes down to what you pay for, and how you structure the investment. Damn, sounds harder now right?
If you are really hung up on rental return I'm guessing that to get both you are looking at buying a duplex (front and back, or maybe 2-3 units/townhouses on a block) where you maximise the rent you get per sqm land purchased.
Then again, depends on your $$, your patience, your negotiation, your patience, luck, experience, knowledge, patience etc etc