For the past three years, I've grown almost all of my CPs under cool white fluorescent lights. They were 3-9" under 160W (4 48" tubes, 3100 lumens each, 4100K) on a 15h photoperiod. For the most part, they've all done fine.
That said, I just switched (as of a week ago) to fluorescent "daylight" bulbs (GE 40W, 3050 lumens, 6500K). As you can see, They put out just as many lumens as a cool white fluorescent tube but they have a better K. I got them on sale for not much more than the cool white tubes would cost. All other lighting parameters are as before. We'll see how they do.
Be careful basing your decision on lumens: it is simply a measure of how much visible light it produces (to the human eye). It tells you little about how much light is actually efficiently useable for photosynthesis. Another almost useless parameter is CRI which is a measure of how close to its "true" color (color under natural sunlight) an object's color is under the light, based again on what it looks like to the human eye.
PAR and, even better, PUR are better parameters to look at for the purposes of picking a bulb for your plants. Unfortunately, this information does not come on the packing for most bulbs. A bulb with a K of 5000-6500K produces good light for plants. The higher the K the more energetic the radiation. Cool whites put out ~4100K and are centered around "green" light. They are generally considered less efficient lighting for the purposes of photosynthesis than the daylight or sunlight bulbs, but the experience of many (such as Joe) puts that into question.
Of course, in my opinion there are a couple of things to consider when buying a bulb:
1. Expense: Just how much more efficient are the expensive daylight and sunlight bulbs compared to a combination of cool and warm white lights (or cool whites alone)? Is this worth the expense?
2. Efficiency: Any bulb can be made more efficient by placing it closer to plants, by increasing the photoperiod, and by surrounding the plants with reflective material such as mylar.
So, find the bulb that best meets your lighting (and wallet's) needs!
Ken