How many miles are on the injectors? Because if you are at of past 150k the injectors are likely just worn out and no amount of special sauce is going to fix them. Injectors have a service life, plain and simple. Eventually they must be replaced to restore idle quality and prevent misfires.
As for oil, everyone should be running Rotella 5W40 T6. Running cheap oil in a 6.0 is false economy when you consider how important the oil is to not just bottom end longevity, but also HPO system longevity.
Personally I'm not a fan of all the additives. I've run all different kinds over the years and frankly I think they're all hokum. At one point the Diesel formulation lacked a lot of lubricity, and during that period it was a good idea to run some fuel system additive, the best of which I found was a quart of TWC-3 non synthetic two stroke oil in a full tank of fuel. But, fuel formulation is constantly changing, and they have the lubricity issue fully addressed at this point, so the additives are not really doing anything for you now.
On the oil side if you're going to try anything I would run the Archoil because of their money back guarantee. But I'm a firm believer in running T6 oil and changing it every 5k. Doing that I see no real need for an oil additive, and find it worth noting that every oil manufacturer specifically tells you not to use additives with their oil.