We keep talking about Kimetsu's anime, but right now, the question is whether they can get the character design down. WIT Studio with Hozuki's team should be able to recreate the dark, gritty with a tingle of comedy atmosphere. Otherwise, they should try a team akin to Mononoke's anime though that's again your despised Toei. At the least, a character designer like Hashimoto Takashi who was also animation director on Mononoke should be on board. Bones keeps coming up but you're going to have a long wait as they're fully packed all though next year and honestly, while they're versatile, I personally don't think the atmosphere of their works fits. Noragami would be the closest to Kimetsu and even then the feel of the series is still different though not to say they will be unable to pull it off.
Pointless to bring up Mononoke now, I agree that something similalr to its aesthetic would be fantastic, amazing even, but that was freaking 10 years ago, a lot of things have changed since then. I did say, that the most important thing for me when it comes to the adaptation is that whoever adapts it respects the artstyle and understands how to implement the cuteness and comedy properly, it'll be hard.
The thing about Bones is, they can do pretty much any style if they want to, it's honestly shocking how good they are at approaching any kind of character designs and any aesthetic in general. Even if they have nothing similar in tone to Kimetsu at the moment, they can easily pull off Kimetsu, their shows have vastly different atmospheres from one to another.
You say WIT, I do agree they are a good pick, but they're as busy as Bones, or even busier. They didn't even do season 2 of Hozuki because of how busy they are, next year they have the second cour for Magus's Bride, Love is like after the Rain in Winter, 2 Donten ni Warau movies, Season 2 of AOT which is likely 2 cours long, an OVA or 2 for AOT, and potentially another season or a movie sequel for Kabaneri.
Bones have Bnha 3, which is likely also 2 cours, they have 1 show from Shinichiro Watanabe, which could be an original or an adpataion, we know it's a music project. Their original Aico incarnation finished production this year, I said Netflix are only releasing it next year because they want to dub it into multiple languages. They have a Bungo Stray Dogs movie and an Eureka Seven movie. I'm kind of hoping Bones end up adapting Kodansha's Fire Force though, that would be a blessing, an anime is coming soon for that I think , based off the fact that Kodansha recently made a Twitter account for the series and they're heavily promiting it, I talked in more detail about this in the Weekly Magazine topic. SInce 2014, Bones have done between 4-10 cours of anime in a year, WIT have a much smaller output.
The anime would only come in 2019 anyway, so they're 2018 stuff will already be over with.
