Banks: .970, 156
Aaron: 1.037; 182
Aaron was of course a better baserunner, though he hadn't stole a lot of bases at that point or in that season (8 SB, 0 CS). Banks of course played SS which is big.
Fangraphs says Aaron's WAR was 9.0, while Ernie's was 10.4... advantage, Banks!
Addendum: In 1958 Willie Mays had a WAR of 10.7 to Ernie's 9.7. And in 1965, Mays had a WAR value of 11.5. Not too shabby.