4 light fixtures are very much more expensive than 2 light fixtures and then theres the cost of the bulbs. You don't really need four lights You just need a 2 light fixture with wider wings. I have 2 with a 13 inch width on a table 3 feet by 4 feet and they work very well. I can get 6 trays under them. The ones in the center get a bit less light but I move them around every time I water. I have them connected to a power bar and that's plugged into the wall. I have seen them with a 9 foot width and that would be fine on a shelf. The major thing when buying lights is to have wings so the light is concentrated downward. I would check all the hardware and big box stores that you have in your area on line. You might be able to find some on sale and them you can go into the store. As for shelving look in resale stores or second hand stores and think outside the box. Remember you have to hang the lights on something so I'd stick to wood

I'd go with the cheap T8 fixtures from Walmart and overdrive them. It's easy to do. I made a tutorial on it with step by step instructions. How to overdrive a T8 fixture They are a little warm but no concern about fire. I've been running the same one for 3 years. Completely safe. Here is a link that might be useful: How to overdrive a T8 fixture

Home Depot carries the Armacost brand in some stores. But the Armacost website has a lot more selection for lengths, light temperature, and brightness. We tried to use the Armacost for our undercabinet lighting. It looked great, provided perfect even light, and was easy to put in. But we didn't like the reflection on the granite. Instead of relecting pools of light like from pucks you saw a line of little light dots all the way down the countertop. My wife didn't like that. That might not bother some people, and if your counters aren't shiny it won't be an issue.

Thanks Patricia....I'm not opposed to puck lighting but my other surrounding cabinets have linear under cabinet lighting. I thought the pucks might look incongruous. Correct me if I'm wrong. BTW, if I go with the strip lighting on the floating shelves, my cabinet maker will route out a channel so it will be flush with the shelf.