Is budget a concern? Some of the lens combos mentioned here are obviously top of the line, but they also come with a price. 70-200 2.8 II, 24-70 2.8 II, 16-35 2.8 II. Who wouldn't want that combo? However, new, these lenses will run around $6500 plus any tax that applies. If the OP can afford this fine, but not many people have all these lenses or pick them all up at once. The f4 zooms are a bit more affordable. Maybe the 70-200 f4 IS should be considered. It's really sharp, light and affordable. If you have a 24-105, maybe you have overlaps, but that's if you carry everything you own with you. Sometimes you just want one body and one lens. The 24-105 is great for that.