As Bonst said, I'd take ProE over AutoCad. I do work on ProE. Still, there are other CAD programs to consider, Solid Works and Catia (SP) are two that I hear good thing about. Its really comes down to what company uses what program. I hear from different sources that driving trucks is a bit rough right now. HVAC is suppose to be realy good if industrial. Even the commercial or residential is OK. I hear on the industrial side it is/was so competative, you could basically keep you vacation amount going from one company to the next.
Tom