OK, so to play NTSC games on a PAL system, You will need to mod your machine, this can be done with a soft-mod, any region changer will do it, you can run this from the homebrew channel.
To load Homebrew channel, you'll need to run the twilight hack, If you don't have it, rent it or borrow it, don't buy it because you're going to need a NTSC version if you want to play it after changing the region.
If you've updated your system in the last 4 months, you will have 3.4E, and so you'll need twilight hack beta 2 version. otherwise use the original version.
You may want to go ahead and get a hardware mod chip though, Get it in the UK though, they're easier to find there, and you can have it done for you rather than having to buy it online and install yourself.
Mod Chipping will enable you to play all your PAL games you may already have as well as NTSC games, (also copies).
You may also need some component cables because while the TV you used might have worked for your Wii, not all will work well.
You can always buy import games, for reference:- Europe, Australia and HongKong all use PAL systems. I would recommend Mod Chipping though.