I thought long and hard on that very subject when I built my booth. I ended up using fluorescents (those same under counter ones you've mentioned) with the reasoning that they took up less room, and as an added bonus were cooler in operation than incandescents.
I suppose there is a chance that they are a fire hazard, but, they are all sealed units, so the fluorescent gases can't get out, so the paint fumes shouldn't be able to get in. Incandescents run too darn hot to sit that close to. LEDs would be the coolest in operation, but I wonder if those little puck lights have enough wattage to do an effective job.
I think if I had that booth, I would get a fluorescent fixture, and enlarge the whole on top to fit the fixture. I use one "cool" and one "warm" tube in mine, and find that the light is pretty good and seems to be fairly balanced. Using either one or the other colors the light unrealistically.