Through-hole keyboard kits are a test of soldering skill but also shouldn’t be an extreme challenge. When I built a Mysterium through-hole TKL kit the biggest challenge was to get it to look good and consistent because I didn’t own a diode bender. There have been a few similar boards with an Alice layout, I can think of the Sesame for example, and now Novel Keys is selling the Seigaiha Keyboard Kit.
The Seigaiha PCB silkscreen alone looks amazing and at $95 it sounds expensive but that is close to a bargain for an in-stock mechanical keyboard kit. Granted, you’ll still need switches, stabilizers, keycaps, and soldering equipment but it should be a wonderful project. Here is the link.