Been thinking of doing this for over a year and finally got round to it. Found parts. Spent hours soldering, lubricating, stuffing with foam and programming QMK. So happy with the final result. It's a joy to use.
Gateron yellow switches. YMDK PCB, backplate and case. Ali Express keycaps.
It's a budget build and none of this is high end......but it has still worked out really well.
If you have more money than time, then you can find hotswap PCBs and pre-lubed switches; and that will mean all you've got to do is press the parts together. Soldering and lubricating are the most tedious parts.
Problem is, i sink my disposable income mainly into anime-merch, so far without regrets.