Power strips and surge protectors are two separate things. I studied them extensively online after I bought my Plasma tv to give it some protection from small voltage spikes.
Overall, :"good" power strips does not mean expensive, but its actually hard to get a good one.
I use two currently at home. One is a 30 dollar brennensthul power surge protector and one is a cheap surge protector by HAMA or Belkin or similar (cant recall now).
The cheap one gives issues even with my laptop display when connected through it.There is a clear snow/grain effect that becomes more apparent the longer the signal has to travel (to my projector, its 10M).
The one by brennenstuhl not only has no issues over all, but when my fridge in the living room stops its cooling cycle, it holds power to my speakers for under a second (yet my tv does not turn off), so its possible it even stops low voltage swings (those that most electronics actually can handle, but is never good for them), thou obviously not confirmed.
In terms of audio quality, there will be a difference if the power strip, power surge protector or power conditioner is uses the wrong protection model. If not, it simply wont since the transformer of your amp will basically negate any imperfections (at least to such a degree that the human ear cannot notice the difference).
When you talk about noise, the most common comes from magnetic or electrical interference (Laptop, close to a big magnet like a subwoofer).
I for one do not believe in expensive cables or power conditioners... unless your electricity provider really stinks.
And what you've said is relevant to my initial comment because?