IDT that enclosure will be large enough for an adult panther. For an adult panther, 24"x24"x48" is recommended, which is ~16 cu ft. Those dimensions yield ~9 cu ft. —about half.
I agree 12% UVB is too high. Note the 12% is for desert dwellers like bearded dragons, ackie monitors, or uromastyx. Panther chameleons live on the edges of rainforests. Arcadia 6% or Reptisun 5.0 are plenty. I also agree with using a meter—either Solarmeter 6.5x or
DIY version.
You will also need a basking light and LED plant light.
For basking, I prefer (in order of preference):
- Household incandescent bulb (not LED)
- Incandescent flood light (not LED and not spot light)
- Halogen flood light (not spot light)
A
clamp light fixture works well for basking lights.
Basking lamps are best installed/mounted at an angle to produce a temperature gradient rather than a hot-spot.
For plant lights, I prefer LEDs, specifically for a 24 x 24 x 48 enclosure I like/recommend:
https://www.sansiled.com/70w-led-grow-light-full-spectrum.html
Coupons are usually available.
LEDs are generally more powerful, last 5X longer, don't contain mercury, and many (like above) are self-contained and don't require an additional fixture.
I try to set up lights like a Venn diagram to allow the cham to seek out/find the light it wants/needs. This isn't as important for plant lights except that plant lights are often the brightest in an enclosure and reptiles instinctively try to bask under the brightest source.