There are so many choices and ways to do it, it's almost silly to work it out so far in advance. Also you didn't say where you live.

On Star Alliance, you could fly any combination of United, Lufthansa, Swiss, Austrian, Lot and SAS. In fact if you use miles, you have to call United and ask about availability, but you'll probably get some combination of those airlines.

By next summer US Air will probably be tied with American, rather than with United (merger or no merger)