If you credit to OZ, you will be *S for 2 years (20k), and only one more long haul away from *G for 2 years (40k). The miles are good for 10 years, which means that you do not need to worry about using them any time soon. A3 is a good option as long as you will be able to directly with them at some point in the near future. TK will also give you *S for 2 years, with *G at 45k miles. Just about all of the other programs have much higher status thresholds, will only grant you status for 1 year, and the miles expire in 2-3 years. Alaska status is of little value if you are not flying with them.