I have a gaggle of them that I got from Batfish Aquatics. They are effing awesome. Keep in mind, you will need to learn to anesthetize them and trim teeth. They do eat snails, but can be lazy about actually crunching through the shell to get to them. I can teach you sometime, or you can check out some of the "small puffer dentistry" tutorials.
When you QT them, assume they have ich and hike up the temperature/treat them for ich. They almost always have it whether you see it or not, since they are super susceptible.