Black Sex-Links usually are pretty dark brown with some light hackles, sometimes not even black at all. But actually I think you are right Nsampsel, those little guys in the corner look like Black Stars.
I also agree with you, Thinking it's Delaware/Colombian Rock, but both breeeds have yellow shanks, this guy has pink shanks. So I'm guessing a mix between..
A nice big rooster. His hens next to him, their combs are like 3 times as small as his, as for the wattles also. And notice his tail feathers, those nice big rounded ones are sickle feathers. Only roosters have those.