of the three guns you describe, the sauer sounds like the best bang for the buck...
also, gunsmith usually can safely open Sauer chambers to 2 3/4"...but still keep loads to under 1200 psi...
and b&p comp one are wonderful loads for old and new guns...
Bad, bad advice regarding chamber lengthening and 1200 psi. 1200 psi isn't enough pressure to barely open the crimp and would be perfect to roll shot out of the end of the muzzle. Maybe you meant fps, but fps generally isn't related to pressure (psi), but man alive, 1200 psi is a burp and a dribble...