We used the 18" version of Good Earth's low profile light bar.

We visited in person, not online, a large lighting store, not a big box or Amazon. One of the sales staff did most of the under cabinet sales. There were several different styles and prices. He was able to answer all our questions and gave us excellent advice and outstanding service. We decided to have ours switched at three different points just for our preference. Every morning, I switch on the coffee bar. In the afternoon while I am cooking, I use the lights on that wall. In the evening, for those snack trips between movies, the area by the sink and fridge is lighted. On the other hand, if we had used undercounter in our previous home, I would have wanted one switch. Take your plans with you and ask for the most experienced sales person in the store.

Use LED tape/strip lights in an aluminum channel. If you want the lights to be as unobtrusive as possible you can can embed a flush-mount channel in the underside of the cabinet. Otherwise, just attach a surface-mount channel to the underside of the cabinet.

Use a channel with a plastic diffuser to reduce reflections of the individual LEDs in the countertop.

Most LEDs operate at 12 or 24 volts and require a driver to reduce the 120 volt household voltage. You can use one driver for all the lights; just run low-voltage wiring from the driver to the the three LED/channel sections. Connect the driver to the house wiring* and hide it inside a cabinet. Be sure to use a dimmable driver so you can dim the LEDs from a wall dimmer. Put the switch for the undercounter lights in a convenient place such as adjacent to the kitchen light switch.

*You can direct-wire the driver or plug it into an outlet.

P.S. I almost never use my undercounter lights, just the lights in the ceiling.

P.P.S. I like to figure things out myself. This isn't rocket science.

Thank you all so much! My contractor recommended a lighting store :) And I think the flush mount channel is so cool.