It's important that you use something that will deliver the correct amount of power to the console. If you use a UK power supply and plug it into that console, you'll probably end up with a fried console.

We do have quite a few folks in here that can probably give you more specific suggestions.

The NES power supply technically makes 9V 60Hz AC, however there is a rectifier right at the input of the console, so it shouldn't matter what frequency you give it, as long as it's 9V.

To answer your question, yes, the Sega Master power supply (9V DC) should work.

someone please correct me if I'm wrong lol

i've been using a pal nes power supply in my pal nes and my ntsc nes for 3 years and it works perfectly in both. no clue how electronics work but i've had no problems doing that