Good outlet for amplifiers

I confirmation of others before me, the Furutech GTX-D NCF(R) Ultimate Nano-Crystal Rhodium-Plated AC Duplex Receptacle produced an audible difference.  
In reviewing your system, I do not see power conditioning listed.  I recognize your post focuses on outlet recommendations, but consider a power conditioner within your means from Shunyata or Audience.  Well kept preowned is good.  IMHO, more of an improvement across the board than an outlet.  

@pinball101 Wouldnt I get a better connection, at least to the first outlet, by going directly into the outlet rather than creating a pigtail in the box? That’s what I was thinking and why I would Daisy chain. Because the most important outlet will be the first one where the two amplifiers are set  also, this quad installation is the end of a circuit… So I’m not too worried about other outlets further downstream.

I can't speak to the benefits of direct connection vs the pigtails in line with the connection.  But based on your configuration being at the end of the circuit, I would not bother with the pigtails either.  

I'm not familiar with the isolated grounding you are referencing so I can't speak to that either.

@peter_s  I hear you… But I would also have to construct my own cables in that case. I’m using power cables that have plugs on them.

Your attempting to improve the 'weak link' which is the connection of the PLUG its self.

None of these connection changes will give you more power/high voltage or cleaner electricity or less noise. The only reason for upgraded outlets is for reliability concerns.

Whether ANY of the solutions will give you an audible improvement is doubtful but if you want the absolute best, most reliable connection available eliminate the plug altogether.

Good luck!

To be clear, there’s nothing good about an outlet plate, especially a metal one coming loose and at best putting the ground up or down is a prayer to the angels at best.