I decided I didn't want to risk missing out on the indiegogo discounts, so I ordered the standard wifi+4g unit, and a camera module. Everything else will be available at some point I'm sure, and the mystery of the USB-C to HDMI cable, and what kind of hub, can wait!
Hopefully they'll start to ship them out in quantity very very soon. I'm really stoked, I've tried all sorts of USB and bluetooth keyboards with my phones, and considered the Moto Mod keyboard, but only the latter and the Gemini have really offered what I want, and I'm also very enthusiastic about a proper linux handheld along with an active community to make something special!