Nothing special about the down lights as long as they are suitable for zone 1. Most shower down lights are rated ip65 as these were.
Whenever I do niches I initially make them extra big (just build the framework) then when you get to the stage of setting out you can finish the build to suit.
Whenever I do niches I initially make them extra big (just build the framework) then when you get to the stage of setting out you can finish the build to suit.