I don't really want to put a zeta on DN for the tiny chance it makes the littlest difference. I don't see it as something that will make the difference vs maxed out JTR or NS teams.
As for mods I'm missing about 5 speed on both palp and Vader but I don't think it's enough to swing the balance. If I could get a god set f speed mods to get palp to 240 I'd be in better shape but that's either months of farming or thousands of dollars. Vader doesn't accomplish anything against JTR anyway because he only applies dots to 2 targets due to foresight.