1. Mod-chips enable the wii to run other region games on your wii as well as enabling them to run burnt games.
2. If your wii was bought before about september you can use any of the first/second generation modchips on it. The best ones atm are the Wiikey and the Cyclowiz.
Both work on all wii regions and have automatic region patching (no need for regionfree).
3. The way that your wii is bricked (ruined) by the mod-chip is when you update your wii with a different region game update. E.g an American wii with a Japansese smash bros game. However to stop this either update your wii to the latest version before updating via the game or apply brickblocker (
http://wbb.rockman18.com/) to the game iso before burning it.
4. Although not all japanese games work on NTSC-U and PAL Metroid prime a major nintendo product worked.
5. If they put in new protection the mod chip community normally fixes it quickly. In the case of mario galaxy it was cracked before the game actually went retail.
6. Modchips are readily available in Australia.. check the local selling/buying magazine.
7. Since they are illegal in America it is harder to find but many websites ship there from overseas.
So to run brawl.
1. Purchase / install ( or get a pro to install) a wiikey / cyclowiz modchip.
2. Apply the updates for the chip available from there websites.
3. Update your wii to the latest version
4. Import or download your japanese copy of brawl.
5. Apply brick blocker
6. Play Brawl.
Jesus big essay :S just couldn't stand all the misknowledge about modchips haha