The Wii was designed for reading pressed discs, so, no matter which format you choose the console will be somewhat "overworking" to read it anyway. What you can do to minimize this is to use high quality media, which is what Verbatim and Taiyo Yuden blanks are.
By the way, the disc diameter and thickness are standardized so that all DVD capable devices know what to expect (e.g. how to "grab" the disc on slot loading devices/etc).