That's correct, left side only. FYI: The safety is actually a safety/decocker, which is nice for carrying purposes. After I insert my full magazine I rack the slide and load a round in the chamber, at this point the hammer is cocked. Then I use the decocker to drop the hammer. The pistol is now safe to carry as it is now double action(first round only) and safe to carry with the safety off. When you need it just draw and blast away. If you like you can carry with the safety on, but it's not necessary. Plus it's confusing for me because it works in the opposite direction as the thumb safeties on my 1911 and Browning Hi Power. ie: down is safety on
The standard 3913 and 3913TSW are ambi, the LS and NL variations are left side only. I have a very rare 3914NL, and it's left side only.
Any 3rd gen gun is a good choice, but the compacts are really good for concealed carry for self defense. My 5906 is the most accurate pistol I own, it makes me look like an Expert shooter, which I most assuredly am not.
If you aren't determined to get a stainless gun, there is also the 3914. The problem is that they are pretty rare since they were only made for a couple of years before being supplanted by the 3913.
The "Value Line" guns are a good deal too. They are a bit more boxy than the 3913s because part of the cost cutting was to not machine the slides as much as the "real" 3rd gen guns. Also, some parts were replaced with plastic (mag release being one) to save money. Some value line guns come in both blue and stainless. Four Seasons had a bunch of them about a month ago, but they sold fairly quickly.
I also made some comments on the 3913 over in the thread about single stack 9mms for EDC.
The 6906 is the double stack version of the 3913, so all of my comments about the 3913 apply to them.
Great guns. Unfortunately Smith discontinued them a few years back to concentrate the M&P and their 1911 models. The only 3rd generation guns that *might* be in production are the 4006 for the CHP, and the 4566 for the WVSP. There are rumors that they still make full size 9mm guns for the LAPD and NYPD, but that is probably not true. Those have been updated enough that some experts (not me) refer to them as 4th generation guns.
There is also a DAO version, the 3953/54. The 53 is stainless, the 54 blue. Again, very unlikely to find them in MA, but some agencies down south used them when they transitioned from revolvers to semi autos. They so show up as trade ins in other states.
Finally, a 3914DAO was made for NYPD as an authorized off duty weapon. The big difference between that is that the 3914DAO has second trigger pull capability without cycling the slide while the 3953/54 require cycling the slide. The authorized NYPD firearms dealers were clearing those guns out at $600.00 about a year ago.
Other than that, I don't know anything about the 3913 family of guns.