You can theoretically make your own single layer PCB but be careful with the Chemicals used , there are many tutorials online now like at Sparkfunhttps://www.sparkfun.com/news/2116
In the MMJoy2 Folder you will find the PCB Folder with some example .Lay6 files which can be opened with Sprint Viewer .....Sprint Viewer (not Demo) will allow you to Print them to PDF, I used them to make my own Shift Register Boards with 2x 74HC165chips but I just used ProtoBoard for them , I didn't etch my own.
Note that different MMJoy2 Firmwares come with different PCB examples and not all of them are 100% correct.
The Magnets need to be Diametrically magnetized , 6 or 8mm round will work slightly larger if it has a hole in the middle for mounting.
If you buy the TLE Boards from AliExpress, they come with the magnets.
Most of this Info is in the Thread too, especially from when I started my 1st Conversion and had all the same questions , I think I started here about page 119 ....
Magnet info page 138=142 ?