Canon 6D MK II: Zoom Lens Recommendation?

[Shampoo]

Brother has this camera and has instructed me to garner advice on the best lens for his needs. I've been told that the focus will be architecture/city shooting and something around 135~300mm telephoto.

Can some folk chime in with a good recommendation. Thanks.

 

[Shampoo]

Can you do me a favour and link me to that specific Sigma 100-400mm c on the rainforest. Not PC-related so shouldn't be an issue for the forum mods. I just don't want to forward him the wrong link by mistake!

It'll work with his EOS 6D Mark II out the box no worries?

 

[Shampoo]

Thanks, gents. Bought.