I’ve found Canary Mail to be a reasonable equivalent to Airmail.
However, I generally use Mailplane, as have several G Suite email accounts, and keeping their respective email, calendar and contacts organized in one place has worked well.
Also, since it is an ‘overlay’ on Gmail’s web UI, it also does a good job of supporting any Gmail extensions that I’ve installed.
Mailplane’s email (Gmail) does work well with Hook. I’ve just posted the integration scripts in the Share your Hook Scripts topic.