MARRIOTT BONVOY BUSINESS™ AMERICAN EXPRESS® CARD has upped the bonus (until 10/23) on their business line cards too 100,000 after you use your new Card to make $5,000 in purchases within the first 3 months. There is a $125 annual fee.
While I don't have a business, I was able to get approved via "Sole proprietor". I've used that for other business cards without fail as well.
Other perks with the card are there too, please look through the webpage and see.