Since most of your flying is on AA, have you considered a Citibank AA card? I realize that you have one for business, but if you are keeping all expenses separate...
I am sure that someone here can point you towards a good miles for sign-up offer.
Another good option is Diners Club (also a Citibank card, BTW). They have some of the best point-to-miles conversions, and are certainly prestigious enough, if that sort of thing makes a difference. Acceptance can be a little spotty, however.
[This message has been edited by notsosmart (edited Jan 31, 2004).]