The $100 bonus promotion from the Discover Business Card is going away on December 31st. You can earn a $100 Cashback Bonus when you make $1000 in purchases within 3 months after your account is opened.
In addition, there is 0% APR on purchases for 12 months, so there is no hurry to pay the whole balance off right away. Just keep in your bank account earning interest. Finally, you can get 5% back on office supplies, 2% on gas, up to 1% on all other purchases.
As with all these business cards, individuals can apply as sole proprietors by simply using their name as the business name. You just need to put your Social Security number as requested, and leave the Federal Tax ID blank for this application (it will use your SSN). More details here. More $100 bonuses listed here.