You might add the FIM outlets to your list. These list for $60 each.
I am using PS Audio Power Ports wired to a 20 amp dedicated circuit. I replaced Pass & Seymore 20A hospital grade outlets with the PS Audio's and feel they were a worthwhile upgrade. However, there is a significant amount of material concerning this subject on this site. Someone mentioned members Hdm and Lak they seem to have done a fair amount of research,therefore, I would recommend you read their posts.
I recently went through the same process. Based upon the other threads on this site, I opted for Albert Porter's cryo'd Hubbells (aka Porter Ports). These went into my wall outlets (on two separate dedicated lines, from a breakout box/circuits BEFORE my main service panel). One line (for pream/source) was all Belden 83803 12AWG, and the other was for power amps, and used 10AWG Romex (the 9AWG Bedlen 83806 was a bit too pricy for my length of run). I also had an existing, shared line receptacle replaced with a Porter Port (this is for TV and VCR). Out of the Hubbells, each line (including the shared line) feeds a PS Audio Ultimate Outlet. Two are the standard UO's, and each of these had their receptacles replaced with Porter Ports. The one feeding the amps is a 20A High Current Ultimate Outlet, and as the HC already comes with a Power Port, I left it as is. From there, I have two custom made 4-way boxes (each using two Porter Ports) with in-line switches and using the 12AWG Belden for the preamp/source and 9AWG Belden for the amps.
Ernie Munier supplied (and partially assembled) the Belden wire and breakout boxes. I picked up the cryo'd Hubbells from Albert. Both of these fellow Audiogoners are extremely helpful, very professional individuals, and I highly recommend that you make contact with them. Of course, they may not agree on EVERYTHING! ;^)
While I was not able to dissect the individual benefits of each and every component of my AC upgrade, the net effect is quite audible. Most notably, my low end has really strengthened, and the highs seem a bit more smooth. Also, where my amps would show signs of distortion before when I started really cranking them, now, the distortion lights are unlit pretty much no matter what I do.
Hope this helps, Tom.
I have not tried any of the above mentioned products, but this is what I did to my outlets. It's a worthwhile improvement at a relatively low cost. I first identify all the outlets along the electircal feed between the main panel and the outlet where I connect the stereo system to. These outlets typically are in the same room but double check to make sure. Next, I upgraded all the outlets to industrial grade outlets. Typically, when an electircian install an outlet, they plug the romex cable into the spring clip hole instead of tightening them with the brass screw. When I tried to reterminate them using the brass screw terminals, the screw frequently get overtightened and came loose. You won't get that problem with industrial grade outlets. Home Depot sells them for about $12. You can even upgrade to hospital grade outlets. The bottom line is, I was able to tighten all the outlet connections using industrial grade outlets. Was there any improvements? Honestly I don't know. But the upgrade made sense.