Not sure about citra but amarillo is a proprietary hop and growing is limited to a select few in the US (thus rhizome availability is next to zero). Citra might be the same story.
It would probably be easier to buy a plane ticket to WA / OR, hire a car and go scouting for a sneaky midnight dig'n'snip, followed by an international smuggling operation....
Than it would be to buy Amarillo or Citra rhizomes in OZ.