1. You should be able to find the guitar only on ebay, or at a gamestop if you are lucky. You can also order them directly from red octane at their website.
2. Not sure if this has been fixed or not, but the initial batch of GH3 discs for the Wii are done in mono, not stereo, not dolby digital... fucking one speaker mono. You also miss out on downloadable songs, online play, and any future updates/patches.
http://www.redoctane.com