I would definitely recommend US Airways - generous legroom, the best IFE in the skies and all at a reasonable price. However I would certainly try and route via CLT rather than PHL. PHL has quite a reputation as the Bermuda Triangle for airline luggage, a reputation I can vouch for in the light of multiple personal experiences! Also if you're flying in the winter months, PHL is more likely to be affected by adverse weather than CLT.