As far as I know...Helix only makes the DBS-1000 (for our type of application). If you meant what type of thermostat should you get, a helix or any of the herpstats are all good choices. A temp gun would be a good investment too.

I would say if you have entire rows without snakes, remove that row from the power so you are not paying to heat nothing. Just make sure you start heating them back up at least a few days before you expect anything to be in them.