compact full size....
- 1800 layout - cherry g80-1800, tkc-1800, drop shift, etc.
- compact (some separation) - Macally MK96, cooler master storm tk, data desk Lil'Big Board (originals were alps, not sure about current)
- squashed (no separation) - Keychron K4 or similar
f-row less (can have f-keys, arrows, etc in firmware with key combination)
- usually based on the M0110a layout - apple M0110a, the key dot co Molly, etc.
specifically made for small hands
- datadesk LittleFingers (pretty sure it's rubber dome)
http://www.datadesktech.com/desktop_base.html... now that i think about it.... look at a bunch of the wireless keyboards for tablets. they are usually smaller keys and condensed layouts
you could space normal mechanical switches closer together and try the typewriter style keycaps, or have someone custom 3-d print you a set that would work with the tighter spacing.
- standard spacing is right around 19mm i believe (including the keycaps & tiny gap so caps don't rub/collide/catch each other)
another thing to look into is getting into firmware layers. so the board can be small like the olkb planck but have all the functionality of a full size board and more.
one thing i think is silly is the control & shift keys on the outside edges of keyboards, why make the most used modifiers the furthest away? i think control(command), shift and alt(opt mac) should be close to the center of the board for use with your thumbs.