Do I need upgraded power cables?

Based upon the recommendations from @erik_squires (very knowledgeable), I recently purchased a Furman P-2400 AR (the 20A version of his above recommendation) and the Furman PSD 8D, with very good results. 

The 2400 provides voltage regulation, conditioning, surge protection & isolated banks for analog & digital (6 each). I use it for my main components & is full. 

The 8D does everything except voltage regulation, with 4 each isolated banks. I use it for my secondary components (6 of 8 outlets). 
I purchased both for less than $1,000 ($3,800 retail). Highly recommended. 

On upgraded PC’s, never A/B’d, but just bought them… Audioquest NRG Z3 for amp, Y3 for remaining components. Reasonably priced & look good. Don’t know if they improved SQ, but did once buy a Pangea PC that actually degraded sound, so reasonable to assume one would see improvement with the right PC’s. 

One more thing, IMHO isolated banks for your analog & digital components is critical, unless you run two dedicated power lines & 2 separate power conditioners.
When installing my 2400, I accidentally plugged my turntable into the bank I was using for digital, and a digital component into the analog side. It sounded terrible, so I can personally attest to the recommendation to separate analog & digital.

OP, many recommended plugging your amp directly into the wall to not starve the amps draw when using a shared conditioner. Two things:

1. Most are high power amps, tubes and/or mono blocks.
2. Most have installed whole house surge protection, eliminating the need for your conditioner’s surge protection.
I have a lower powered amp (Moon 330A), no whole house surge protection & never play my system loud (sounds great at lower volumes). I have my amp plugged into my 2400 & feel I am loosing nothing while adding protection. YMMV