The guys who make the HD Retrovision cables did some testing on some inexpensive UL rated power supplies and suggested this one from Amazon, which you can add adapters to to use with tons of different consoles.

https://www.amazon.com/dp/B001BRKFII

I have it and it works great with my Genesis and Super Famicom. They list the adapters you need here:

http://www.hdretrovision.com/vote3rdparty

Everything I needed was less than $20 and it seems like a very reliable power supply.