Here are my facts.

AS/DL relationship ending. I will likely fly DL about once a year, sometimes more, sometimes less. I also fly AM on rare occasion (but will continue to credit to AS as long as that lasts). Most if not all travel is in paid (discounted) premium cabins.

I also fly intra-South America on paid tickets from time to time, and while I prefer LATAM, would fly AR on short hops, and this is my most likely redemption (i.e., SCL/BUE) for wherever these miles end up. I'll likely never have any status (unless I ask for a match, which I wouldn't want to waste anytime soon) nor will want credit cards, etc.

So, I need a bank, and not sure if DL, AR or AM would be the best bank. I'm also totally unfamiliar with all of them.

Comments, suggestions, et al., please! Thanks.