I recently purchased a 5D2 and 70-200 II f/2.8L IS and I'm looking to fill out the lower focal range. I also have a 40D with the kit 17-85 lens. Generally when I go shooting, I go with my wife. She carries the 40D. I tell her it will be lighter for her to carry, but I'm pretty sure she is on to me 😄. I promised her that we'd upgrade her lens, but I want to have the flexibility to switch lenses with both bodies. So it would be for either the 5D2 or 40D.

Need some help deciding on one of the following (or any other lens suggestions):

1. 24-70 f/2.8L (I or II)
2. 17-40 f/4L
3. 24 f/1.4L
4. 24-105 f/4L

Right now I'm leaning towards the 24-70 because of the IQ and range. But I'm not sure if I'm sacrificing a lot on the lower focal range for landscape shots. I'd like to use this for landscapes, say 65% of the time. I'm trying to get away with getting a zoom to cover the rest of the range without opting for an additional lens. But if having the best (or significantly) improved kit means I need to add another lens, then I'd prefer to start that now instead of getting something that I will end up selling and upgrading less than 2 or 3 years later. Thanks in advance for your advice.