Cham, just a couple notes!
For the moon, long is good, in fact unless you want to try renting something like a 500 or 600 for a night, I'd say you really need 400 (maybe a 100-400) and get a 1.4x TC to bump things to 560mm.
You also might want to consider shooting with the 40D rather than the 5D. The 40D will actually give you a better resolution for the moon, since it will still take up a relatively small portion of your image. The big advantage of the 5D, though, is the viewfinder -- big enough so that if you need to resort to Manual Focus the viewfinder will help a lot more than the 4D one. But try a few things -- AF, Manual Focus on Infinity (Not the symbol but the inverted L mark (read your lens manual) and Manual Focus using the viewfinder. In general the more shots you take trying various things the more likelihood of getting a set of great shots.
I mentioned ISO 100, but you can certainly go higher -- a fast shutter speed is important. And, like I said, you can get good results by slightly underexposing the orb of the moon. Unless you are very careful with those highlights it's easy to end up with some clipped ones which can look ugly. In fact, something I've done with good results is to actually meter on the moon, and center the meter so that the camera tries to render it medium -- it sounds strange for something so bright but I've been pretty satified with how well it keeps the details and shadings intact. You could, in fact, try an exposure bracketing around that setting and then you can see what works best for you.
Speed is critical not because it emits light but because it is moving, and something very important about getting a great moon shot is the ability to have sharp, crisp detail that you can enlarge and it just stands out with craters well defined and such.
Know also that from my experiece a moon shot can take a generous amount of sharpening in post processing to get that detail to pop even more!
