With regard to the credit card part of this I think you have limited options. Virgin did have cards issued by MNBA, that was pulled for new customers a few months back. I understand they'll be a new Virgin Atlantic card issued by Virgin Money, but what it'll offer is not yet published. I don't think AA, Delta or Cathay have their own UK cards. So for them it would be either an Amex rewards card, or perhaps the Amex SPG one, whichever allows transfers to your preferred program at the best rate. Amex rewards transfer to either Delta or Virgin at 1 to 1, although I think there is a minimum amount that can be transferred. With BA SPG points transfer at 1 to 1, but 20K get a 5K bonus, so packages of 20K SPG points convert to 25K Avios, maybe Delta and Virgin do the same, perhaps worth checking.