1. Yes the ashida can fit all three. There are 3d printable mounts that
@Senor Avocado made for the MX chip as well some wifi antenna brackets. You can find those
here. Mounting these modules isn’t a standardized thing, you can always just mount them on an any empty spot in the ashida with some kapton tape.
2. Either are compatible with the ashida(U-amp is the more flexible board)
3. I believe aspect ratios must be set manually on a game by game basis? I’m not sure about this though so someone else may be able to help you with this
4. This is your choice. The pms 2 is the more capable board, offering efficient 1v8 voltage regulation(better than the wii LDO saving 10-15 mins battery life) and battery life estimation. However it is also more expensive than the pms lite
5. From what I’ve seen, if you want transparency, use pcbway’s SLA clear resin option(UTR-8100). But keep in mind, resin prints can be very fragile
6. For buttons you could get a classic controller, a set of buttons, and an extra z button, or you could get a gamecube controller plus an extra z button(You can get these from ebay). I would recommend going with the classic controller, they are really cheap and use the same components as the gc controller. I would harvest the potentiometers from the controller you buy.
7. I got my wire from amazon. 22 awg stranded wire for high voltages, 30 awg wrapping wire for in between things, and 34 awg magnet wire for wii vias and data. Make sure to get multiple colors of each to make the build process easier
8. You should not need a micro sd to usb if you are using the pms pd 3 from 4layer tech. Any sd card formatted to fat32 should work
Hopefully these answer your questions!