I could see having a black Ben - which would also give us a black Elliott Stokes. I still think that Ian McShane would be great in that part, but there are of course many actors who'd be good in all these roles.
I could also see a lot of logic in casting a black Angelique. From what I've read white servents in Martinique in the 18th century was unheard of, as slaves were so commonly used in that time. That wouldn't make much difference in the dynamic in the modern day at all, but in the past time periods it would make a huge difference. Angelique as a black woman in the 18th century could never marry Barnabas, but she could still be his lover. Off the top of my head I can't think of an age appropriate AA actress who I think would make a good Angelique, but I have to struggle a bit to find any younger actors anyways, as I don't keep up with young actors as much as I do older actors.
I think Nicole Kidman would be perfect as Angelique, she has the right look, and she could do those gorgeous soulless blue eyes for Angelique very well.
I do think Susan Sarandon would be great as Julia, except she's probably 30 years older than Zachary Quinto, not that it matters. Any reboot is sure to push the Barnabas/Josette clone angle anyways. But also, Susan Sarandon is gorgeous for any age.