@sstallion Hi! Yes, the PowerBlock does some software debouncing. Please contact me at contact (at) petrockblock.com and I can send you a firmer with the momentary button support disabled. I have this, in fact, already prepared.

@suleske I found several inexpensive and simple circuits I could build. This little board has some added features (e.g. setting the key press switch delay), so I bought it: https://www.ebay.com/itm/262199569276

@maksi opens the RGUI menu - https://github.com/retropie/retropie-setup/wiki/retroarch-configuration

Go to this website: http://www.makeuseof.com/tag/add-reset-switch-raspberry-pi/
And look for this section: "Give Your Raspberry Pi A PC-Style Soft Reset Switch" It's about 1/3 of the way down the page. (the entire page has relavent info though)
The section I'm talking about has this video:

As long as you have a rev2 or newer Pi, you can add a simple reset switch that'll work how you want.

Minor soldering (adding a 2-pin header) involved. You can just solder the switch directly to the header if you need to.

Note, I've never actually done this myself.

Yes, the second one you linked. you would connect your power in to the microusb port. The full USB port would go to the PI's micro port. Blue/White would go to GPIO. Power switch would be soldered to switch +/- connections... If you could fashion something to use the reset switch, you could connect that to the reset connections. You can also connect the front led to the LED/Gnd ports as well... (GND is shared between reset and led)