Current UAL MP Balance - 28,702
Current Delta Skymiles Balance - 6698 (Million Miler- 8625)
Current AAdvantage Balance - 15,000
Current FlyI Balance - 1400 points

Base City - SDF or CVG, both are equidistant from my location.

Frequent travel to EWR, once/twice yearly flights to LHR/LGW, and semi-regular flights to RDU.

Looking for suggestions on an airline and mileage program to shoot for while banking segments/miles doing corporate travel.

Thanks for the help!