Your 86* now-warm side can become your cool end---snake doesn't care which is which...and w/the CHE (try the 100w) on either a dimmer or the thermostat, you can adjust it until it's the 92-94.
I had a screen lid on my 30g breeder & the CHE in a heatlamp hood w/clamp sitting on the screen, but I had to turn it off and on to keep it from getting too hot. (This was before I learned about the dimmers and thermostats.) Just be careful to put SOME sort of regulator on it, because they're VERY good at what they do, and can get VERY HOT.

R