Just a few easy comments...
Our local Graybar is selling basic Raychem kits at a price that breaks down to less than $2 a foot.
I can't speak for the other brands mentioned...Raychem is the only one I've seen that is self-regulating, and can be cut to length. It is also not damaged if it somehow gets crossed over itself- an important concern with older types.
The system I installed last year included lengths of cable to run into gutters and down downspouts.
I believe the reference was to an "Equipment protective device," which is essentially a GFI breaker set at 20ma. The system I put in just used GFI breakers; so far, so good.
Oddly enough, I think the NEC exempts rooftop ice-melt receptacles from GFI requirements. I say, follow the mfr. instructions.
