i have only seen flexwatt at expos and even then its a long shot check out bigappleherp they have about the best price/s&h combo ive seen plus have great customer service.
and the diff is flexwatt will heat a strip of 3", 4" 11" or 17" wide for as many feet as you cut it and a cable will heat a strip bout wide as your cable tv for as many feet as you run it. not sure how many watts cable is but flexwatt is only 20 watts for the 11" and i wanna say 6 for the 4 dont know the others off top of my head