Blackberry might be worth a look?
TBH though, the only reason I would ever recommend a BB these days is because of the keyboard. In almost every other way, they’re inferior to Android/iphone/Windows.
As for Android, I think you’re going to struggle to get an all in one unit. The last time I looked, there were only two on the market. That was about five years ago, and I don’t think the market has improved. For whatever reason, there just isn’t a market for them any more.
Based on what I’ve seen in the past, even if you do find an Android phone with a keyboard, it’ll be crap, overpriced or both. Best to abandon that idea.
Have you looked at Bluetooth keyboards? There seems to be quite a range out there of various types. OK, so you’re stuck lugging an extra device around with you, but that’s probably going to be the best way to get what you’re looking for.
Blackberry’s got an Android slider coming out soon, the Priv. Unlike most sliders I’ve seen, the keyboard slides out from the bottom in portrait mode.ETA: I guess that is as small as the iPhone. I still picture iPhones in their pre-iPhone 6 size.