I agree with Tvad. There are so many variables - no one can answer this for you. Overkill is doing more than you need for your setup and your gear combo. Some systems and decent power need NOTHING. Some gear combos and dirty power need a LOT.
Dedicated Lines & Power Conditioners
I currently have a Running Springs power conditioner in which all of my gear is plugged into. The RS is plugged into one of my two dedicated lines. Is this overkill? Could I get away with a less expensive PC? Does one really need high end power condtioning when using dedicated lines?