As far as building your own pixels and strips, looks like that requires some specialized equipment that most of us don't have on hand. Don't they use some form of injection molder to encase the nodes? My guess is the flex strips are made on a continuous assembly machine that can crank them out in a few seconds, verses the hours it would take to manually place all the chips on them yourself.
Now if you could find someone with that equipment in the US that would be able to do it, that would save the money in shipping we end up paying, which at some point RJ mentioned he is working on doing that. We just have to have patience.