Not really brand focused, but if you want a decent product Asus, MSI, Gigabyte, EVGA, and any common brand will have their offerings if you are looking into a laptop with an external Thunderbolt dock for a GPU.
Also, laptops with the mobile Pascal chips will come soon, Asus, MSI, Razer ( not a fan but w/e ), and build to order laptop companies will offer them for a relatively normal price.
I would get one with an i7, 16/32GB DDR4 and a 1080m ( or a desktop 1080, if they do the same as with the 980 )