Overkill? True, unless you are also running a mondo rack or a whole room full of rig/amps off one regulator unit...but still, a PL Plus or Monster Conditioner would work fine for just a single Mark IV and some other stuff like effects, etc.
I've run 3 amps, my effects chain and the studio computer rig off my PL Plus with zero noise one day just because we ran out of sockets and it didn't even barely clipped into the yellow. I'd say it's a good investment for the money.