I have a stair light installation that goes like this. Core drill 2 1/2'' hole in a exterior poured stair wall curved no less. Fixtures selected are a Line voltage GU10 MR16 with a 5' low voltage lead attached (fixture company spec). I am thinking of doing one of two things, using a butt crimp inside the core hole with 1/2 pvc out the back each pvc will run to a exterior gutter, or 1/2 conduit daisy chained from hole to hole with fixture make up in each hole. Back side of stair wall is open now, but will be back filled soon. Total of 11 lights to install and L.V. is not a good option due to a future pool installation that would put lights to close