If you want Wii and Gamecube games at a higher resolution than you can get natively from the console, you can either build a nice PC to run dolphin and run the games at a higher internal resolution, or you can get an upscaler like the xrgb-mini.
The first, it is expensive to get the games in 1080p with no frames drops, and it isn't the same experincie than playing it a console, and for the second, isn't that similar to the upscale that make the Wii U now? I don't know the xrgb-mini what exactly does, that's why I'm asking.