So I'm looking into possibly going back to part 121 once my training contract for my 135 gig expires or at least pro-rates down to point where I can pay it off. Likely Jan/Feb of 2019

My question here is, where to go?

I'm 37, I live just outside Chicago (so ORD/MDW ideal bases)
Masters Degree
I have 3500 hours total
900 Turbine (all jet)
150 PIC Turbine
and around 160 hours of 121 time from years ago.
No accidents, incidents, no failed checkrides, no DUIs or other disqualifying factors.

So to ideally stay in Chicago, or at least get back here from a short stint commuting, what is my best option? Envoy? Republic? Other?

Don't quite have enough time for the LCCs, but being 37 I don't want to be stuck either.