alpaca jumper, with your low flying patterns (by FlyerTalker standards) any program where your miles won't expire/won't expire while keeping active/using a credit card would be the best. I'm personally not so good on NA programs, probably some other users might help more here, but if an Aeroplan account with a credit card would keep your miles from expiring, then probably choosing them would be best.

On the other hand, if you could manage to make 19k miles within 1 year, or 3k miles in one year and then 16k miles in one year, A3 would have *G status for you, and apparently miles in their program don't expire...