I also recommend the H&S MiniMAXX for the DPF delete.
Negatives for removing cats: illegal EVERYWHERE as it's a federal requirement to have them on any vehicle post '85(?). Vehicle can be impounded right then and there if cop really wants to.
Negative for removing DPF: more black smoke potential (is that really a negative?) but check your local laws first. Do you live/travel anywhere that does diesel emissions testing? If so, you're up the creek without a paddle.
Pros: SO many... better MPGs, no clogging DPF, no wasting fuel burning off filter, better airflow out = more power.
My suggestion, delete the DPF but leave the cats. You can get a 4" or 5" turbo back kit for the truck that includes the DPF delete pipe. I'd also delete the EGR cooler to reduce the intake temperatures, and since you're deleting the DPF the NOx will be out of control anyways, so why not go all out and destroy the atmosphere some more!