Assuming Kerevi and Tomane are unavailable, I would play Genia, Foley, Hunt, Lealiifano, Kuridrani, Folau, Beale. I would have Lealiifano for goal kicking, but if not I might pair Kuridrani and Folau in the centres and bring in another wing with Sautia playing there.
Folau, Kuridrani, Hunt and Sautia could be spread around the centres and wings as they can all theoretically play both positions.
South Africa might look at the strength of league relative to rugby in Australia, note that they are both competing for the same athletes, and decide they'd rather keep rugby as it is.
It's amazing how league players only seem to move to rugby union late in their careers when their best days are behind them, or if younger then only when big money's involved. How many top players under 25 have moved to rugby without huge riches being attached?