The only way to get too much potassium is if you are taking a potassium-sparing medication for high blood pressure. In which case I would not recommend adding a supplement. You don't *have* to take supplements, it's up to you, but if you start experiencing symptoms you can just pop on here and tell us what is going on and maybe we can give you an idea of what may be going on. Usually a need for more potassium manifests itself in the form of light headedness and/or extreme tiredness.
As for me, I take a lot of supplements, which I vary as I deem a need or no longer need them.
If you eat red meat at least twice a week, then don't take one with added iron. Inorganic iron, which is what vitamin pills have in them, has been linked to severe problems, which is why it is actually easy to find iron-free supplements these days. Organic iron is the best way to get your iron and you get plenty by eating red meat.