S is not Scorpio. despite how awesome that name is, the Xbox One X is the Scorpio system. the One S is like Xbox 360 slim, I think. Someone else feel free to correct me.
But yeah, Microsoft decided that Project Scorpio was going to be the in-house name for the One X.
Also, after catching up and reading a bit more, you’ll definitely want to get an external hard drive if you intend to use it and own multiple games, unless you have really fast internet in which case it really doesn’t matter. all you lose on uninstalling a disc game is the updates, and if your internet is fast updates don’t matter.
You do not lose any save data as far as I know when you uninstall a disc from the hard drive, it just frees space for you to use for other games. (I assume it works this way, as PS4 and Xbox 1 seem to be nearly the same console thus far, and that’s how it works with my PS4)