i use a belt for my top lifts also, to me it feels like i have a little more support, plus i have two bda disks and i dont like to take too much chances...
i use an Inzer economy power belt... 10mm thick 4 inches wide and the same size all the way around.... if you use a cheap nylon one, try out a good thick leather belt, you will never go back to the other belts, i promise you...