Should apply, yes, even though I never imported any british PS2 Games. But...why would you need to import something from the UK? It seems like you´re in the US, don´t you have all you need there?
There are a few games that were released only in the PAL regions.
I'm pretty sure there are some decent PS2 emulators out there that can run the disc straight out of your drive, and your games won't look like shit. It's a lot cheaper and easier than modding your system, too.