What is an excellent power cable?

I guess my budget is around $500

I'd contact Patrick Cullen: http://www.cullencable.com

I just received three of his Gold Series cables (10 AWG).  Patrick's cables are very well made and well within your budget.  I don't think you would be disappointed.

Cullen Cables are fantastic. Over the last six months I've replaced all my cables with Cullen. Very happy with the results.

Cheers,

Scott

Might want to try Rob Fritz’s Audio Art cables. Great construction quality and a nice evenly balanced SQ. 

I've had great results from Clarus Crimson HC power cords for my amps and Kimber PK-14 Palladian for the other components. 

Flyby?  OP??  You still out there somewhere???  Anyway...

+2 Cullen Cables for your budget. Take advantage of free trial. And yes, power distribution is VERY important. Here’s a very simple and popular power distribution strip that doesn’t have any crap in it to muck up sound...

https://www.alliedelec.com/wiremold-l10320/70091760/

Best of luck.