I added the BOM for the LED modules to the git repo. For the provided AliExpress shopping links I didn't use the cheapest configuration possible, depending on what type of LEDs you use its a little more expensive than 1.3€ incl. PCBs but also more robust. I will add links for the cheapest config as well.
I also ordered some first PCBs (so far I only tested on milled boards) which came out really nice. Here some picture.
Also a few pictures of plant progress: