Whoever is using sourcesafe in 2011 really should have read this a long time ago. I really wouldn't recommend it in any case for technical reasons. And in 2011 there really isn't a reason to pay anything other than hosting costs for source control -- the FOSS solutions are perhaps the bestest and most mature until you are building something on the scale of, say, windows.
As for the dreamweaver FTP feature, I think any of these solutions would work with it. If it is actually testing on a remote test server (bad mojo, but that is another debate) then you probably want to save/test then commit to the repository once you are done.
As for tools and such, if you are on windows I would probably shade towards mercurial over git. Main reason is that windows tooling is quite a bit better and more mature and features are on par in general. Hosting-wise, bitbucket private repos are a lot cheaper than github private repos. The $298 for the first license of that source-un-safe product could get you a 25 user private account over there and leave enough left over for a beer or three.
If you are committed to git, at least on windows the tools are a bit ugly. Git for windows is your only realistic option and it is definitely a bit limited and a bit ugly. But it definitely works in most cases.