5DIII + 24-70/2.8L II is an excelent combination for general use.
70-200/2.8L IS II is just about the best zoom lens available (the uber-expensive 200-400+1.4x notwithstanding). Great indoors and out for portraits, but not small or light.
17-40L is a good ultrawide lens for landscapes, as long as you plan to shoot mostly at f/8 - f/11, it's fine. The 16-35L II is double the cost, gives you an extra stop of light (useful for low light) and better IQ at f/2.8-f/5.6 (better, but still not stellar).
70-300L is better as a travel lens due to its smaller size, 100-400L is better if you'll use it mostly at 400mm (I have both; before getting the 600 II, I used the 100-400 a lot more, but now that I have the 600 II for reach, I use the 70-300L a lot more than the 100-400).
For architecture/landscapes, I'd consider getting a TS-E 24L II or TS-E 17 over the 17-40L, budget permitting.
The combination of the 70-200 II + 2xIII is optically similar to the 100-400L at 400mm, but the 100-400 is easier to use and focuses better. If you'll only use the 200-400mm range occasionally, the TC may be the better way to go.