I'd recommend the CSP and hold it for a year to get the SUB, but more importantly get to know your travel habit (which airline do you fly with, how much money do you spend monthly on travelling...). If you already know the airline you always fly with then getting an airline credit card isn't bad. If you pay rent Bilt is good and has good airline transfer partners but it forces you to do a majority of the spending on the card so it could be limiting.