Australia quite easily. Especially when you consider AUS pace depth ATM.
As already mentioned Ntini got dropped because he was finised as test bowler. SA 3rd choice paceman is Parnell ATM, but De Wet when fit.
So overall if you add up first XI options plus pace depth of both sides:
AUS: Bolinger, Hilfenhaus, Johnson, Harris, Siddle, George. All 5 have played tests & except for George ATM, all are quality. Shout outs to other talented youngsters who have been bowling well in sheild cricket, but i have not seen yet expec for J Pattinson such as Starc, Copeland
SA: Steyn, Morkel, De Wet, Parnell, C Alexander, McLaren, Tsotsobe, E O'reilly (Francois Plaatjies & Quinton Friend are also a few names that have been spoken about).
Off this crop of who have played international cricket outside Steyn/Morkel, only De Wet is quality ATM. McLaren is decent but is basically suited to bowling in SA conditions, while i have been impressed with Alexander. But the rest are either unproven unknowns or crap (Tsotsobe).