lamps always cause lower humidity, but you can combat this a number of ways: sphagnum moss, a damp towel laid over a hide, regular misting, bigger water dish, water dish under the bulb, covering any mesh tops with plexiglass or a damp bath towel. and i don't think you need to use the second UTH; keep working with your bulb and regulation until you're hitting optimum temps.
like i said above: keep adjusting it until you're hitting 77° F. is the bulb regulated by a rheostat/dimmer? or a thermostat?
also do you mean thermoSTAT instead of thermoMETER? they're two totally different things and the distinction is important in this hobby.