Hot light for propagation chamber help needed please?

[Subrosa]

Look into HID fixtures designed for landscape use. A 150W-175W metal halide or high pressure sodium will do the trick. The only potential drawback I see is that these sort of lights are not instant on, requiring a couple minutes to warm up before reaching full brightness. While this isn't a major problem, these lights also require a cooling off period after being turned off hot. This
could easily be half an hour, so if the temperature of the chamber fluctuates too quickly there could be issues keeping temps withing your defined range.