As far as the Black Panther suit, I think it should be adaptive so that they could use all the looks.
What I mean by that is, the base suit would be classic Kirby, jet black, no ornations:
Then, he's climbing. Retractable fingertip and/or foot claws:
Those ornations on his forearms? Kimiyo Cards that can recess after use.
Maybe when he's in a fight, retractable knuckle claws:
You get my drift.
Obviously, a balance would need to be struck because you don't want it to come off as goofy, nor do you want it to come off as the the suit is really the power and not Black Panther himself. But in this manner, we can get all of the looks with one suit and have it make sense, with the added bonus of showing to the audience just how advanced Wakandan tech is simultaneously.
I've never been a fan of the kneeguards like the one in Boom's post. They're so big and obtrusive looking in every image of BP I've seen with them.
Mackie would make a good candidate for Falcon (as would Laz Alonso), but I can't see Mackie for BP.
I'd prefer an African or at least someone with direct African ties to get the lead role as opposed to an African-American. I feel like there's a very important distinction there.