Your chain question has already been answered but I just want to clear something up. Bicycle chains from 5sp to 11sp all have the same inner width, i.e. the distance between the sideplates, and the same pitch, i.e. the distance between the rollers. What varies in those chains is the outer width - as the number of gears increases the thickness of the sideplates decreases. I found conflicting info when I researched this before with sources stating that the difference was between 1.5mm and 2.3mm. Since that distance is halved due the sprockets/chainrings riding in the middle of the chain there is effectively around a 1mm difference.