I like the idea of using them as a super tough 3 man unit. Aside from the benefits of solo models when controlling zones, flags, and objectives, They will make an excellent second wave.
I was looking for a way to set them apart from the rest of the army, but not look as if they don't belong. I toyed with the idea of painting them in the Armor of Mourning from 'Superiority', but I wasn't convinced that it would look right. Instead, I chose to paint them oppositely from the rest of my army, that is ochre armor and white cloth.
I am very happy with the results, and am excited to get them on the table top. The last 3 lists that I have built contain all 3 of these dudes; Amon, Reznik, and Feora 1.