The best place to get box art for all the game systems since the PS2 used to be cdcovers.cc. Unfortunately the site was abandoned years ago, and now all the links are broken. Now I use covergalaxy.com. They don't have nearly as many covers, but it's better than nothing. The main site is infrequently updated but the forums are active and members often contribute covers there. I don't see either of your requests though. The Wii had so much shovelware that many of the less popular games just don't get scanned.
