You can get a guarantee of a King Bed if you pay for it. There's a King Bed category. As far as requesting AB is concerned, you can request it, but it's not guaranteed. Please don't make the same mistake I did. I'd requested a room in AB, and was so excited to try it (previous 5 trips I'd made no such requests, and always been in the mansions). Well, you can guess what happened-got to the front desk-mansions again! And no rooms available in AB, they said. I moped around for about 2 hours, wasted 2 valuable hours of WDW fun time because I was too busy feeling sorry that I was "stuck" in the mansions again. No matter that it was a mansion I'd never stayed in with the nicest view ever (Magnolia Terrace). When I finally scolded myself a couple hours later and headed off to Epcot, I had the greatest trip, and the nicest room. But 2 hours of "valuable fun-time" wasted!