I'd wait for a correction, then: NST : weight 5 bread and...

I'd wait for a correction, then:

NST : weight 5 bread and butter, probably 2x.
ARD : weight 2 explorer with transparent management, 8x.
NCM: weight 3 77Moz of reserves, enough said, 3x.

I picked the two biggest producers market cap to encapsulate the largest number of mines in Australia, throwing in an explorer for a gamble. Cheated with NCM because it has debt.

You asked for 3 stocks to take advantage of the sector, rather than the best gold stock. Individual small gold companies can screw up due to mine failures, floodings, legal problems, wet roads, worker strikes, etc. So I think picking the biggest companies is the way to go. I still weighted NCM less than NST due to debt issues.

EDIT: They are not junior, and I don't think I'll only invest in junior miners if I'm to bet on the sector, sorry.