I feel your pain. My choices are only Comcast Cable, Verzion DSL, or Satellite which is just about as fast / slow as Dial up.
You're most likely going to need to upgrade to a business plan. Surprisingly some of those business plans are about the same price as the home plans, so typically you're not going to need to pay to much more. But shop around... They'll always try to charge you a higher tier plan.
I recommended DSLreports.com because not only do people go there.... So do the ISP's. Can talk to everyone from customer to provider directly and have people weigh in on it (I've been a member for over 5 years, OldSchoolDSL).
I'm not 100% sure about At&t at the moment, because they seem to change often. And I know their support is a pain in the a** from what I've heard. You're better off asking people who may know more than I do.