Randy, all reptile specific heat lamps are dimmer safe, provided you use proper light domes and dimmers.
UTH are designed for heating under tank with a substrate on, but for pacman frogs you can't use as they intended to. When used attached on a side they don't heat up tank much, therefore you need to use them bigger then your tank volume, very rarely that you can use only UTH for pacman frogs and have proper temp range.
people are having success combining UTH on a side with infrared lamp or ceramic heater, it is a difficult, but not impossible to achieve.

The best is to use hydrotherm controller, plug everything in it and live worry free over humidity and temps.
there are different controllers, but in substantially higher price range.