I own a business and currently hold a Platinum Amex. 1 of my biggest suppliers DO NOT take amex so im forced to pay with Visa or MC

So I got the chase debit card with United Miles.

Couple things that suck are that
*United does not fly out of Dallas much at all.
*I cant get another Visa or MC that will give me a large enough spending limit like my amex a month. 40k a month
*If they took amex i could get the black :/

Any suggested as what to do in this situation?

Also important is that I have multiple stores and the accounting is done seperate so getting 1 card with 2 names is fine but year end summery has to show the exact breakdown for the accountant.

if this thread needs to move no problem

THANKS ALOT IN ADVANCE!!