You are correct that CMH is junior for FOs. PIT is also junior. So is LGA. ORD is not. If you are planning to commute, consider LGA for the faster seniority increases and thus shorter time on reserve. However, avoid commuting in general. A two hour drive to CMH or PIT gives you a shorter commute time than flying to any other base. Your life will be much better that way.
I was based in CMH for a couple of years. There are plenty of crewmembers there who drive two hours to get to the airport. It's not all roses, though. Plan for early show times and late finishes. If at all possible you will want to work 3-5 day trips to minimize how often you have to leave your house at 3 AM.