Apparently they sold all their equipment related to CF driveshafts so they aren't producing anymore. I suspect they have a few left for warranty related claims but no more for sale. As mentioned above, I believe a friend of mine who is a vendor has a hold on the last one.
I think thats the wrong PN for the headlights - check compatibility section. Still on sale though!
https://www.morimotohid.com/morimoto-ford-mustang-15-17-xb-led-headlights_3?quantity=1
There isnt a ton of gain with headers normally anyway, right? I'm purely thinking about this for sound - any power increase would just be the cherry on top.