I have gotten a good number of these retro computer kits from different makers, and thought I would start to make a catalog of them. Please let me know if you find others! They are in alphabetical order of the original company that created them.
Summary: I quickly put together this kit; with no issues it can be a nice afternoon project. It offers USB and Bluetooth connectivity and comes with a preloaded controller and SD card. A newer edition than mine now exists with an Acrylic case instead of the older bamboo one (even though I think that makes it cute).
Summary: My first kit, running off a Raspberry Pi, Oscar put together a great beginner kit. This is the 2015 model, which had you paint the switches. Newer kits have a closer to “historically accurate” switches.
Summary: Following the great PiDP-8 kit, Oscar followed it up with a replica of the PDP-11. This kit shows how much Oscar has grown creating these, with a plastic injected case, and (compared to my 2015 kit) much closer switches, this is another fun kit that anyone can dive into.
Summary: One of the more professionally put together kits I have done. It comes with a metal case, as well as the ability to remotely connect over WiFi and then interact with the system. You pay a bit more for the fit and finish, but the project comes out looking great!
Other kits I have seen but not bought/constructed:
Emulating: Commodore PET
Emulating: Spectrum 128k
Random ones in no particular order: