Why not try the "Chapter 22 Alliance" US & UA. I am one very happy camper on US, but there service is limited into SNA to just a few flights. UA however dominates the west coast in the same way US does the east coast. Upgrades are easier on US than others. Assuming they both survive you get the Star Alliance for award travel. Read both FF programs very carefully and decide on MP or DM, Even though I am stone loyal to US, next year I am going with the Red Carpet Club instead of US Air Club, more clubs in more places that I go to. Also Envoy Class to Europe is super on US. Conde Nast did a survey of Envoy/business classes to Europe and US came in fith! i was kinda disapointed until I noticed all the one above US were foreign carriers. Good luck hope I helped.

Also the CO/NW is a good deal too, I am a silver there so happy hunting.