I'd get a cantilever slug barrel and a low power scope like maybe a 2.5x or a red dot and shoot sabot. In my expereince they transfer much more energy than smooth bore slugs. As far as fast follow up shots go I don't think there should be a difference at all. For Sabot loads I'd look at the remington Core-Lokt and and the Winchester Partition Gold, and jsut see what patterns best in your gun.