The size light is dependent on your basking temperature. You will probably need either a 75watt or 100 watt basking bulb. Definitely get an infrared temp gun... don't use the stickers.

I would not place a basking bulb above the UTH. That could be extremely dangerous and is unnecessary. As long as your house is above 68-70 degrees, you do not need supplemental heat for the dragon (besides the basking light of course). If your house drops below this, add the UTH but only turn it on after the basking light is out.

Ceramic heaters are fine. It's just personal preference.