I'll do research later, but here are some pointers:
MIDI is now largely USB. If you have old gear, it might still use the old DIN plug, but essentially what you're asking for in the 2nd and 3rd bullets is the same thing. There are still some modules that use DIN, but at this point, unless it has some features that you desire, I would avoid those.
88 keys vs. 76 keys vs. 61 keys -- 76 is much easier to come by than 88, but they're common enough that I wouldn't go less than 61.
"real-piano feel" -- what you sound like you're looking for is weighted or at least semi-weighted keys. Fatar keyboards are the best (often advertised as a feature), but will make the keyboard more expensive.
Its own sound vs. MIDI controller -- a lot of musicians (myself included) use mostly DAW plugins to make their sound, so all we need is a MIDI controller. Even the free versions of Cubase come with synthesizers built-in, which are quite functional. I don't use them, but only because I'm more familiar with the Arturia set of synthesizer emulations.
That said, I'm not recommending it, but just something to be wary of -- don't accidentally buy a MIDI controller and then wonder where the sound holes are -- there aren't any. However if you feel comfortable running your MIDI-controller->computer->speakers, you probably already have the latter 2/3, you just need the MIDI controller and software. It is my understanding that GarageBand is the free equivalent of Logic Pro, but I don't know if it comes with any sound-generating plugins. Free ones do exist, but I don't trust things I don't pay for.
If you just want to start out with piano sounds, and build up your timbral palette with plugins, I would recommend a digital piano. Something like this:
https://www.sweetwater.com/store/detail/RecitalPro--alesis-recital-pro-88-key-hammer-action-digital-piano