Bryan Cranston could work, but isn't Aarron Paul a bit old maybe? Well, not *old* but you know what I mean. If you look at that flashback in the final episode and look at Arron Paul in season 1-2, you can tell the difference notably.
(I think it was in the final episode anyway, IIRC)
(I think it was in the final episode anyway, IIRC)