I need to get a Mastercard to use at the Canadian Costco as AMEX is no longer being accepted.

I've been using a VISA Infinite Avion card and have over 100,000 points on it that I'll need to transfer to another program when I switch cards.

I'm in Regina, Saskatchewan which makes it hard to use my British Airway points, (they don't fly from Regina) which I have from converting Avions, (I now have 45,000 BA points) when they have their 50% bonus transfers.

I also have 150,000 Aeroplan points.

Until November 15, 2014, Westjet is giving a 20% bonus when converting Avions.

Until December 31, 2014, BA is giving a 50% bonus when converting Avions.

Question(s): What new Mastercard should I get and which program should I convert my Avions to?