Starwood is not the best for everything, but it seems like the Starwood Small Business card is what you want. Every $20,000 means 20,000 Starpoints which converts to 25,000 USAir Miles. You'll also make the current bonus, 15,000 extra points for $15,000 spending in the first 6 months.

If you want to travel internationally, for yourself (not your business) you should also apply for the British Airways 100,000 mile Visa now, since the link is back open.