We have planks of wood across the top of our mesh and the dome lamp rests on that. If you put the lamp right on top it might melt the mesh (if it's cloth) or cause it to heat up so if your chameleon touches it might get a burn.
I don't have a pic at the moment but my linear UVB sits on my mesh and my heat light dome I have a. Hook in my ceiling with a chain and my dish Is hung from that 3 or 4 inches above my mesh basking stick Is 6 inches below top of cage
Keep the lights outside. An option to combat the reduced UVB is to get an 8.0 or a 10.0 instead of a 5.0. As for the basking bulb, if the wattage isn't too low you can probably keep it on the mesh, but some higher wattage bulbs will burn the mesh.