Poor snake, doesn't he already have an RI too? Just go to any grow shop or nursery and buy a Hydrofarm. They aren't a Herpstat but they work fine for UTHs and are about $35. And I cant see how you cant get ambients above 70F with even a CHE. Are you using a 60 watt or something? Bump it up to a 100 watt or 150 watt with a lamp dimmer inline to control it.