Prompted by the WSJ article, let me ask this question: What are the best points to accumulate for international premium cabin travel?

I travel domestically very little, and spend about $40K a year on credit cards. I have good credit and churn my cards somewhat.

I need a large supply of Air Canada miles, as my wife lives in Toronto, and I get them by converting Amex points. I get those from spending (Amex PRG is my primary credit card) and I also am able to buy both Amex and Chase points from co-workers, usually at 1.25 cents per.

Right now I have about 350K Delta miles, as well at 90K in a USAir account that will be 100K after the Grand Slam promotion. My wife goes to Europe every summer, with some flexibility in dates, and doesn't mind traveling coach.

What I want to do is have enough miles for two overseas premium cabin tickets every 2-3 years. If availability were equal on all carriers, I would keep earning all the Amex points I could, giving me maximum flexibility to convert to Air Canada for her regular trips or DL for the overseas trips. But all airlines are not created equal. What's my best long-term strategy? Opinions most welcome from those with experience in overseas redemptions.