There are lots of brands out there, every self respecting shop, online or not, carries them.
"softy" seems to have become a generic name, kind of like Kleenex is to facial tissue.
I work with electronics for a living, I buy heatshrink at a local surplus store I frequent often. I also found some super thin high quality heatshrink at Mcmaster-carr. (http://www.mcmaster.com/) Worked well, just be careful heating it so you don't damage your bit. Quick nip with a thin knife and off it comes, $2 worth will do about 30 pipes.
Between the softy and heatshink, I would take the heatshrink because it is harder and thinner.
My preference is neither.
FYI, there is also a heatshrink with a heat activated epoxy inside. Once applied it becomes permanent, hard, and shiny black! I used it to cover a bite hole in a pipe once, worked extremely well.