I don't care what you do but do not buy the 120V puck lights from the orange store. When you put a dish in the cabinet the light flickers and the bulbs don't last but a couple months. JUNK.
The low voltage pucks are ok but whatever you do, do not load the xfmr with even one more watt than it is rated for. Or you will have a similar problem but with xfmr's not lasting more than one month.