Every single lens mentioned here so far would be perfect. All top quality glass that you'll get great landscapes with. But only you know your shooting style. Some shooters will produce their best landscapes exclusively with a 24 TS-E, others will produce their best landscapes with beautifully compressed compositions shot with a 600.
Your choices of the 16-35 f/2.8II & 24 TS-E suggest you like the wide look, but they both go across the same focal length range. I'd like to see you drop the 24 TS-E and direct your $$ to the very highly rated, light weight 70-200 f/4is. For travel work, it's not going to be all 16mm landscapes, you'll appreciate the reach of a peerless 70-200 in ways that you possibly have not even anticipated. The 70-200 f/4is has long been a constant inclusion in travel/landscape shooters kits.