maybe a used Dan Wesson RZ-45 Heritage? Dan Wesson is g2g and well made and down the road can still have some work done if you like?!
I also had no need for NV, so I went with the 512. As far as the submersion, if I'm 10 feet under water and still holding onto my rifle, something has gone terribly awry and I don't think an extra 23 feet is going to matter to me. YMMV
G21 Club #858