US vs UK Power

Hello guys, first post for me here, so I'll start you off with something easy (hopefully)
I'm looking to perform a fairly comprehensive upgrade to my ageing PC, including Motherboard, RAM, GFX card and possibly HD, however there is the possibility that I may move to North America in a year or so.
If I bring the PC with me, will a simple replacement of the power supply to a US spec unit suffice or will it affect other components?

Hopefully you've bought a power supply with a 120/240v selector (could be labled 110/220, etc). Look near the power plug on the back.

I know, damn the U.S. and our superior standards (120v is less likely to electricute people, but requires heavier, more expensive wiring in buildings, 60Hz is better for lighting than 50Hz, etc.).

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