Just to get the details out of the way, please make sure you get the absolute best filters you can. I go for B+W filters personally. Bad filters color the image and introduce all manner of visual aberrations. This is especially important when you are considering L lenses in which you are paying for the utmost glass quality to begin with.
I own the 17-40L, and I heartily recommend the lens. It's a bit slower than the 17-55IS, and lacks image stabilization, but for an outdoor lens (or an indoor lens with flash), you can't go wrong with the 17-40L. What I particularly like are the excellent contrast, smooth, clear colors, lack of CA & flare, and its instant and silent focusing. 17mm is wide enough to stand very close to people and take pictures of them, and 40mm is long enough to get nice standard-focal-length pictures.
I do not own, but have used the 70-200 f4 on many occasions. Since it's f4, it's less suitable for indoors or poor lighting than the f2.8 version of the lens, meaning that you'll have trouble shooting pictures of an indoor graduation, theater performance, or nighttime events. You can do it if you crank up the ISO on your camera, but it's an iffy proposition. If you have the necessary lighting in place, though, the 70-200 is a fantastic lens. It focuses silently and instantly, and has superior color and contrast. It's better in every way than my 70-300IS, with the exceptions that it doesn't have IS, and it only goes to 200mm. When you want to get photos of little birds far away, the extra 100mm comes in very handy. Most photographers who are serious about things like, say, bird photography will buy a 70-200 of some flavor and pair it with a teleconverter to give it some extra reach. All else being equal, though, I'm envious that you're even considering buying one because it is a spectacular lens that really should be part of any SLR collection.
That's a good lead into the 24-105. The 24-105 is an excellent lens. You'll need a flash if you shoot indoors (depends on conditions, as IS will save you in some situations), but in terms of optical quality, you'll be hard pressed to find any problems with it. It opens up decently wide, and it's long enough to give you a bit of extra reach when you need it. The 24-105 is a compromise in this case, though. It doesn't open as wide as the 17-40L, so you won't be able to get too close to a group if you want to take its picture (you may not realize it now, but the first time you stand three feet away from a trio and get them all in the frame, you feel like a rock star). It also doesn't go nearly as long as the 70-200, so if you want to shoot sports or wildlife, you're pretty much hosed unless you can get right up to the subjects. The big benefit of the 24-105 is that you have a nice range of focal lengths in one lens so you won't have to swap lenses.
My personal preference, so far, has been to go with the separate lenses. Having lenses that are more specialized allows for more specific artistic creativity. I also like having the ability to go really wide with my 17-40L and really long with my 70-300. Sure, I have to swap lenses now and then, and I may miss a photo or two in the time it takes to switch, but I figure I wouldn't be able to get the pic anyway if all I had was a single, middle-of-the-road lens. On the other hand, with a single lens you can focus more on the subjects rather your tools, albeit while operating within its constraints. You have to decide which system -- separate lenses or one size fits all -- is best for your personal shooting style. Fortunately, you have your eyes set on L lenses, so if you are unhappy with your purchase you can resell them. The used market for Canon L lenses is pretty good.
Just a thought: have you considered the 24-70 f/2.8L? It doesn't have as long a reach as the 24-105, but it has a wider maximum aperture, making it a much better low-light lens.
Hope this helps...
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