If you want to geek out on this you can buy a voltage tester and a wattage meter on Amazon and find out some very important information about your setup.
You may have a voltage tester already. Measure the voltage at the outlet where you plug in your amp(s). Hopefully it is 120 volts or higher. You indicate that you used 10 gauge wire which is appropriate for a 30 amp circuit (20 amp circuits use 12 gauge wire). I don't believe you stated if you are using a 30 amp breaker and 30 amp outlets. If you used 10 gauge wire for a 20 amp breaker and outlet that won't hurt anything but you are outside standard electrical practice.
Using heavy gauge wire will reduce the amount of voltage loss over a long distance. If you have a very long run from your panel to your outlet, using 10 gauge would moderate the voltage drop. Please excuse this oversimplified statement but higher voltage allows your equipment to run less hard. You can also test for the voltage drop on the same circuit when you are playing your stereo loud. Hopefully it should be minimal.
A wattage meter will measure the draw of a particular piece of equipment. You plug it into the wall and then plug your component into the meter. With an amp it's particularly instructive because you can see how much wattage the amp is using at different volumes. Now you can quit guessing about the current demand of your amp which will allow you to make a more informed choice about the power cord. I'm assuming that your power cord will be less than 10 feet which will have minimal effect on the voltage drop from the outlet to your amp.
Lastly, there are two issues here that should not get conflated. The gauge of the power cord is important only because it needs to be appropriate for the wattage your amp will draw. It's likely that a 14 gauge cord would be big enough to handle the load your amps are presenting and a 12 gauge cord will give you a comfortable cushion. I'm pretty skeptical that you would hear the difference between a standard 14 gauge cord and a 12 gauge cord but if using the 12 gauge cord makes you more comfortable then go for it.
The design of the power cord is a completely different issue. As has been stated above, there is no universal agreement on whether or not boutique power cords make an audible difference so you have to try it for yourself and see if you can hear a benefit. Knowing your wattage draw is important for this, however, because bigger gauge aftermarket cords cost more money. When you get into the upper end cords this could mean a difference of hundreds (even thousands) of dollars between a 14 gauge cord and a 12 gauge cord.