Should All Power Cables be Alike?

Unfortunately it all makes a difference and there's no telling how much of one it will make until you try. Welcome to the rabbit hole!

Hospital grade Hubbell outlets with non ferrous grounding straps are inexpensive, solid and sound decent.. 

Damn. Hope you're well now!
There is no reason you need to stick with the same cable throughout. Some people use the same brand for all their cabling, some mix and match.. I've heard of people that like the house sound of a cable company so much they do all their cables through that company, while I've heard of others that mix and match to achieve a desired sound goal.

It just depends on what it all sounds like to you and what you like.

I'd offer that you should try various power cords on different components using as much reason as possible. Obviously, if you've a power center, you should have a large gauge cord going into it, so as to not limit current (10 would be best, especially if amps plug into it) Power cords to amps tend to sound better if they're larger gauge (12-10 is ideal, 14 is ok on lower power amps). Digital components can often benefit from shielded cords that have the shield grounded. Of course there's disagreement in whether the cord shield should be grounded at the component or wall.. Consensus? Ha!

But really, if you like it and it sounds good to you, that's the most important test.

Yeah, those furutech outlets are pricey! If you're going top of the line everywhere else, they're probably worth it. Otherwise, there are less expensive options that provide reasonable performance. I use Hubbell commercial outlets with non ferrous grounding straps. They were $10/outlet. 

So, regarding wiring.. 10 gauge can support 40 amps. If you have a 20 amp in the wall, it's probably 12awg if you didn't specify using a fatter wire. 12awg is rated to 20amp. 

But for power cables for high current items, like power boxes and amps, going as fat as reasonably possible often improves the performance of the amps. But, again, that's often just for high wattage amps. 10 gauge is as fat as is reasonable, usually. 

But then there are things like cable architecture and materials to take into account. It never ends!

Many members find that to be the case. I hate to keep saying this, but the only way to be sure is to try. I personally have not tried going directly into the wall, but that's because I don't have enough outlets at the wall because I have monoblocks. I plan on installing a dedicated line (right now there are 3 other outlets around the room on the same branch) and another outlet where it comes into the room. Then I'll be trying and deciding for myself as well.
What amp do you have?

@lowrider57 good point, I missed that. 20 amp power cords have different connectors at the component end and will not fit on components with 15 amp IEC inlets. Most components have 15 amp IECs. The plug and connector ratings apply mostly to which IEC and outlet they'll work with. The current handling rating mostly comes into play when taking the gauge of the conductor into account. So a 12 or 10 gauge power cable could safely carry 20 amps of current. But you don't want to get a cord with 20 amp connectors because it won't fit into the back of your amp..

You'll have no problem upgrading the outlets to 20 amp. You'll still need 15 amp PCs to mate with the IEC inlet on your amps.

I've made two of Williewonka's DIY helix design with the sonarquest connectors and yarbo cable with great results over earlier, braided designs using silver plated Teflon insulated milspec wire. Worth the time if you're even remotely interested in DIY.