I would be the wrong person to ask for comparison info. Doing a quick check it seems the 60 is a 5 round and the 64 is 6 round.
The Beretta 92FS and S&W 6906 were purchased by me back in 1992 the others were my fathers. He loved to buy guns but I think i'm the first to shoot any of them.
The 64 is a 6-shot "K-frame" in .38 Special, while the 60 is the smaller 5-shot "J-frame". Earlier Model 60s were chambered in .38 Special, while later ones are .357 Magnum. Both are stainless steel.