new equipment power conditioner or more powerful amp?

I 2nd-3rd-4th the ideas of room treatment and a dedicated line.
Check out ATS Acoustics online if your wish to DIY room treatments. Not difficult to make room absorption panels and relatively inexpensive.

Lots of info on both topics herein on this forum.

I believe in quality of power, not quantity. Not likely you need a new amp, considering power only.

I have a nice system also, but don't have dedicated lines, power conditioning, receptacles or room treatments (although I think my power and room are ok).  I don't have a particular area I can look at (listen to) and say it definitely needs improvement.  Not sure if you have done so already, but I am way behind the eight ball in terms of music streaming, internet radio, and the like.  I am waiting for an updated Sonos Connect to come out.  I believe the other streamers have surpassed the Sonos in fidelity, but I want to wait as I believe the Sonos is easiest to use.

I agree with those that suggest one or two dedicated AC lines along with some of the many good quality duplex outlets, assuming you don't already have them in use. 

One more thought, if you are interested in adding power conditing to your system you might consider the Equi=Core 1800/Core Power Technologies which is balanced power. Walter of https://www.underwoodhifi.com has purchased the rights to this product and I received a sales flyer saying that he has five of these units available at a sale price of $1399 I believe. I've owned this product for several years (since its development) and for the price I recommend it.

I saw this ad on Audiogon: https://www.audiogon.com/listings/lis9d677-core-power-technologies-a-v-equi-core-1800-underwood-hifi...