OmniFlight is one, AeroCare is another, and there's also Native Air. They also use helicopters extensively there. There are more choppers in use per capita in Maricopa County than anywhere else in the country.
As for the stigma...you're going to find that just about anywhere. Thing is, unless you're with fire, EVERYONE works for one of the two companies so it's not like you're singled out or something. It's not the greatest of situations but it's a job and it's not terrible, it's just not the greatest. If hospitals are your thing there are a couple that hire paramedics in the ER but that's not utilized much in the Valley. EMS there ain't great, but it's a job if you're moving there either way.