grwow cabinet questions.....all awnsers will me much apreciate.....its my first build

hi all. i have a cabinet that i aquired. im planing on growing 2 plants. its 28x16x45 inches. i have been told to use cfl lights and mylar......do i need to insulate at all. i will probibly ust 5 or 6 lights. i will also use a cuople of computer fans for the intake and exhaust. what else do i need to think about?