Voltage Stabilizer, Power Conditioner, or both


I know there's lots of discussion of this issue, but I haven't seen a clear answer to this.

Here's my incoming setup:
McIntosh MC207
McIntosh MX119
McIntosh MVP861

With Vandersteens in the front and center; Klipsch in the back.

The room is not treated. I live in New York City in a condo building with all new wiring.

Do I need the stabilizer to protect my electronics? Will either the stabilizer or the conditioner improve sonic quality?

Thanks!
jmprince
After using Monster (which constricted the sound) and Powervar, I now use an APC h15 (the s15 battery-backup one was Stereophile recommeded). At this point, I can't say enough good things about it. It has significant surge protection, isolated outlet banks and voltage regulation.
I live in a NYC co-op and the voltage is all over the place especially in the Summer. I use an Exactpower EP 15A on a dedicated line and now everything is rock solid.