It can't be THAT cold in your basement... My aquarium heater keeps my washes at 75° easily, even though my house temp is only 62~65° at times. How many watts is your heater? Here's some sizing info. I figure 10 gallons for the two ferment buckets, and another 10~15 gallons for the water the heater sits in. Now you need to know the temp of your basement, get your delta, and size accordingly.
Dang table looked bad, so here's the link: http://freshaquarium.about.com/od/heati ... eguide.htm
If your basement is 60°, and your ferment target is 75°, you need 75~100W. I would go larger rather than smaller, to reduce wear on the element. The price difference is minimal.
P.S. I guess I got lucky... others complain about the smells, but my family seems to like the smell. Ahhhh, yeast...