What substrate? If it is something that retains humidity well I'd personally use a ceramic heat emitter instead of the infra red lamp. It has been in my experience that those red lamps and blue moon bulbs DO disrupt reptiles sleep wake cycle. Not for snakes specifically, but I know for sure my lizards see them. If snakes are different then I guess it is fine.

CHEs from 10 years ago are still running here, never had one burn out, dimmer or not. The only problem is they dry the environment a lot, hence the thing I said about substrate and humidity.

Another thing I just started experimenting with this past week with good results are black glass bulbs (NOT black lights). They are just regular incandescent bulbs but the glass is black. They seem to not be as drying but are dim enough that my lizards don't seem to notice. Basically there is a little rim of light around the dome fixture, but the enclosure is pretty much dark. Might want to give that a try.