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!