Building isn’t very difficult.
I didn’t link this at first because it’s pretty small for what you’re looking to do. You would need a bunch of them, and probably cheaper to just build one or two larger lights get you going.
I can point you to where to buy anything/everything needed to build. These are just examples too. There’s hundreds of different led modules you could use. These are pretty inexpensive and very qood performance, so you’ll see a lot of diy lights built with the eb modules. Obviously if you could scrape together some materials without having to buy could make your build cheaper.