You're welcome. I don't know any substitutes for a Herpstat dimming thermostat except an ON/OFF thermostat. You might consider naturalistic enclosures first.
For ~36 x 18 x 18 inch enclosures, Arcadia's 12 inch ShadeDweller UVB tubes & fixtures are perfect. UVB fixtures should ONLY span 1/3 to 1/2 an enclosure's length. Please use tube UVB rather than compact fluorescent bulb UVB.
Create a 70% topsoil/30% play sand substrate about 3-4 inches deep.
A dimming (proportional) thermostat
might allow you to choose different temperatures at night for a DHP.
Place the ShadeDweller & bulb (or DHP) just like this.
[This new chart doesn't enlarge on GU. However,
this same graphic CAN be enlarged when shared online. Just click the +/- buttons on the image's upper right hand corner.]
Please contact me to locate highly skilled experts to determine % mesh top UVB blockage. Knowing % mesh top UVB blockage allows you to determine the distance for a slate basking area beneath a halogen bulb or a 50 or 80 watt Arcadia Deep Heat Projector.
Do you have the brand name? Is the mesh top the same brand?