Which card to use with points + cash on air travel?

[Weezl]

I am buying AA tix using TYP and cash. Do I use the Citi Premier card or the Barclay Aviator for the cash part of the deal?

Also,
I am buying AA tix using UR and cash. Do I use a UA card or the Citi Premier card or the Barclay Aviator for the cash part of the deal?

I want to maximize benefits of course...

Thx!