Seems like the best thing for me might be to try and get the extra 20k miles with US Airways.

Is there anyway to trade some of my Southwest miles?

Is it possible to get miles with US Airways somehow from Chase? I have a good non-rewards card with chase that I could trade, so I think I should be able to get approved with them for a new card. I think I read something about being able to trade Marriot points, or maybe there is something along these lines I could do.