I apologize for the delay in responding, and thank you for posting. Congratulations on the Arri S! Zeiss, Cooke and Schneider primes in Arri standard mount show up on the used market, and older Cooke and Schneider glass gives a lovely look. Since the S is a 16mm camera, make sure each lens covers the 16mm frame and fits your mount. Reputable used-cine dealers and rental houses are the safest places to buy, ideally after a collimation check. Today many filmmakers also adapt those vintage primes to digital cameras. What did you end up shooting?