I think for anything other than brake lights (which you ideally want integrated with the VESC), it’s pretty easy to just wire up and there are a lot of light options available on Amazon. On one of my boards I have a 12V tail-light and a 12V headlight (both from Amazon) running off a buck converter from the main battery. I have separate switches for each light. I’m planning to replace the 12V headlight with a higher voltage unit running directly from the battery.
I also have the TTL system and it’s great but overkill if you all you need are brakelights. The 3D printed TTL lights mount onto the truck bolts and Matt also provides the STL file if you want to make mods.
For brake lights only I found a few bits and pieces: