MVB to me are far better for tall cages designed for arboreal cages....as they push UVB deeper into the cage. For dragons, they are harder to set up..and really shouldn't be the only heat source.
103F in your original temperature ranges is low too. Bearded dragons should have access to 120F on the very top of their basking area...with lower temps on the slops away from the highest points...this allows them to go hotter than the average range (95-115F) for brief times.
Wide angled basking spots or multi-layered tiered style basking areas work best, as the dragons can do what they would do natually and climb up towards bright light and heat to get warmer faster and stay lower areas and shade when they are warm enough. Cool sides are there for them to move completely out of the warmer areas to cool down.
I use ceramic light fixtures that are rated to 225 Watt bulbs...currently i Have 120 wide flood light bulb providing heat and a 4' long UVB 8.0 florescent tube fixture with a full spectrum florescent tube (more for added light and extra UVA light on the double fixture).
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PHLdyPayne