- Corne: You usually have to solder it yourself, and source the switches/caps. A few sites will build it for you. [0][1[[2]
- LilyPro: Same as above. [3][4]
- Georgo/GeorgoPlex: [7]
Trackball: Someone mentioned a vertical mouse, those are really great, but I have been pushing trackballs on a few colleagues. A good in between is the newer logitech, that has a tilt mechanism, but its a thumbball. [5] You can find more options in at r/trackballs [6]. I can recommend the "Kensington Expert Wireless Trackball Mouse" and "CST L-Trac Blue Trackball", although the latter, the original company shutdown and are being manufactured by xkeys. There's also an open source trackball, ploopy [8].
P.s. buying keyboards and soldering them are great for a quick fix, but this hobby gets expensive quick. I am waiting on a few group buys; another 65% keyboard, another split keyboard and a few more key cap sets.
P.s.s. group buys can be a hit or miss (mostly hit), treat them like kickstarters, and maybe you'll get your parts in a year or so. At least in r/mechanicalkeyboards, a few users have recently been complaining a tad more about not seeing the final product v.s. renders.
[0] https://github.com/foostan/crkbd
[1] https://keyhive.xyz/shop/hotswap-corne-helidox
[2] https://www.littlekeyboards.com/products/corne-mx-hotswap-ki...
[3] https://keyhive.xyz/shop/lily58
[4] https://github.com/kata0510/Lily58