Darui seems like the naturall choice since Killer-Bee really shows no signs off responsibility.. Killer-Bee may be stronger than Darui, but there is more than strength that has too be considered being a kage. Darui would probably be the first raikage without ADHD
I agree with this view, and "Lol" to the ADHD remark

. Bee wants nothing to do with being Raikage. He'd prefer to sneak out and learn Enka (I think that's what it's called). He's kind of like an annoying young Jiraiya, annoying because of the rapping whereas Jiraiya wrote what probably constitutes porn, lol.
Bee is not dumb, he's immature and irresponsible; however, he has abilities no one else has. Namely, he has both the controlled power of the 8-tails along with it's vast knowledge (it's been around since the So6P created it via Izanagi, and it's already demonstrated a ton of info such as on the Kin Gin brothers). We've already seen them communicate frequently as well as explain things to Naruto.
However, I don't think it works well to force him into a position he clearly doesn't want. Further, we know power is not what defines a Kage, but merely a component.
Darui is far better suited to the job, even if he's not as powerful as Bee; he still acks a punch with his KG and black lightning.