No one has heat tape they are willing to sell. I guess I am ordering and waiting.

For reference... Flexwatt is not the only manufacturer and this has been around for a lot longer than I knew about.

Calorique as well as a few others make them. They are referred to as radiant heat film. They come in sizes up to 36" wide (ive seen so far) so for those with the enormous 10 ft cages. Or huge rack systems.