Edit: make sure the wires in the screw terminals on the pcb don't have solder on the ends. Clip it and strip it to bare wire or put crimped ferrules on the ends. You can get arcing and fire from the solder softening and the wire slipping out.

All metal or bi metal heat break, or just replace the whole hotend with one of those ceramic heater ones.

Printed locking notched bed level wheels. I used one that had a number of teeth to match the rotation suggestions from the klipper screw adjust macro that uses abl to measure how much to turn each one.

Magnet bed plates. I have smooth matte pei, textured pei, gloss peo, unknown generic textured black stuff, and something else I can't remember. Different filaments work better or worse on different bed materials and get great results without derpy hax like glue stick. I generally do abs on matte and everything else on tex or super smooth.

Printed abl. I use klackender. It calls for jap omron mouse click switch but I used kailh gm8 as a drop in replacement and it works great.

After trying pretty much every z mod I went with belted z from same website/discord/git as klackender. Single and dual drive dual rod and pom nut etc all skipped every now and then but now any print problems are from other causes. It's a bit involved but effort and cost to returns is better ratio compared to the switchwire conversion...

Klipper. You can use basically any computer. I have one on a rpi zero 2 and one with a Dell computer that came with windows but is worse than a bad Chromebook. Both use dietpi as the os and kiauh to set up klipper and mainsail.