Where ever you want
More information would be needed to get into specifics.
FedEx is a very good airline for commuters. But it does take a little seniority to have a decent schedules and good seniority for good schedules.(seniority has been moving rapidly the last several years but may slow this next year if economy continues to slow) Also depends on what type of flying he wants? Our domestic system is best in my opinion with school age kids since it is easier to manipulate your schedule. International is better flying and maybe preferred after kids leave for college.
It really depends on what he likes/wants and where you want to live. There is something for everyone here, but like any airline job seniority makes life much easier.