FWIW, I use the WW Astro dew heater purchased from Sirius Optics on my SCT. Worked well last week here in Sydney when it got cold at night and humidity levels were high.
Looks like they have the smaller sizes in stock:
http://www.sirius-optics.com.au/tele...telescope.html
I found the WW Astro ones quite generous in length compared to the other brands, which makes it easier to overlap and strap them tight on the tube.
All the best in your search. Clear skies!
GR