Had a nice experience with;

Birdland Coach Service
5115 Rosslyn #1
Houston, TX 77018
(713) 682-6323

They are a Prevost qualified service center (according to the diplomas on the wall) and they seem to know their way around the coach pretty well. Good on AquaHot / Webasto and coach systems (OTR AC / CruiseAir / Inverter Power)

Talk to Leslie (a guy). They have a very clean facility in a not so friendly part of town, just off the I-610 North Loop.