PIT- Republic, Allegiant obviously. Wiggins and fedex I believe both have pilots that technically are based out of there. In the case of Wiggins, most of the vans are stationed in UNV, but I believe one or two start their rotation in Pit. I'm about 95% sure I have seen a position advertised for pit for wiggins.

Beaver County has nothing as of now. All of the companies here unfortunately are too unstable for me to recommend them.

Allegheny I'm not sure about

Pittsburgh Jet Center out of Zelienople
Air Quest out of Butler County
Skyward out of Washington county.
LJ Aviation out of Lateobe. Two instructors from the old FBO I worked went there with a possible third going there so they may be set for now.

Akron, Youngstown and wheeling are all not that far of a drive either.