I presumed plugging it into the Wiis usb port would provide sufficient power but I guess I'll wait till it arrives. If it does require 12 volts I'll try bypassing the Stepdown regulator.
If that's the case which I think it might be as it just flashes would the best solution be to try and get the power from the batteries separately
I don't really know how to wire VGA and I would need to install rvloader which I don't plan to do.
How about cellphone/tablet batteries? They are thinner than 18650
Old laptop batteries would be a great alternative definitely, they are thin, powerful, light weight, and hold quite a lot of capacity, only thing though is they are rated for upwards of 14.8 volts (4 cells in series), you could definitely rewire it for 4 cells in parallel, but it depends on the cell structure, which is very inconsistent between manufacturers.
If you don't need/want to keep the disc drive functional, you can remove the drive housing and just keep the little daughterboard PCB in the drive that connects to the motherboard via a ribbon cable and a JST connector. Keeping the disc drive daughterboard connected will trick the Wii into thinking that the entire drive is still there, and allow conventional SD and USB game loaders to work without RVLoader's patches
