The older guidelines for cereal were that it should have at least 5g of fiber (per 1-ounce serving) and no more than 8g of sugar. The newer guidelines are looser with the sugar - just "low sugar."
As for the type, it's mostly a question of what you like. Fiber One should be OK. Most kinds of bran flakes (just bran, not raisin bran) are also fine - even store brands. Most varieties of All-Bran are also fine. Shredded wheat is fine, but shredded wheat & bran has even more fiber. Some people like Uncle Sam cereal, and that's fine also. If you have a Trader Joe's near you, their high fiber cereal is good, and meets the guidelines.
Don't forget, it's not just cold cereals you can have - hot cereals are fine to, and in fact, usually even better. They're usually pretty low-glycemic, and the types appropriate for SBD don't have any added sugar or other odd ingredients.