They both look to be the same so it should be ok. I know the 360 is sensitive to power variations though so i'm not sure if you should get a new power supply, maybe someone with more electronics knowledge would know more.
Also you'll need to buy US games unless your system is modded, UK games wont work on a US XBox 360. Not sure if there's something you'll need to get for your television too, it used to be you'd have to buy an adaptor or all the games would show up in black and white, but maybe modern tvs have fixed this problem.