Republic and Allegiant are the only ones I know of out of PIT. ExpressJet has a CLE base, easy two hour drive. Personally, I'd stay away from the smaller 135 operators in the area. Everything out of Washington County sucks, low pay and ZERO quality of life. LJ in Latrobe isn't that great. Voyager at Allegheny County is always looking for pilots, but you'll be attached to your phone all the time doing organ, CORE flights at 2AM.