Wanda
I don't have much knowledge about the models you're discussing [my excuse for not answering your query, though it does make sense from my limited perspective]. Does Randell/Sundrum mention that a Guth inflation [or any other standard inflation model] could originate from their pre-bang brane model? The reason the Guth model has so much power [at the moment] is because the CMBR WMAP data describes a flat universe corresponding to the perturbation predictions of Guth's model.

Bruce