Listings (Posts?) shared across multisite installations

Hello again,

I started building a yacht listing network but now run into some logistical issues. I would like to use the same set of posts on all sites. Ergo, when I update a post on any site (or a source site) this post is updated everywhere.

I would however like to keep the ability to use different design (templates) and display filters on the different sub domains. A shared posts database comes to mind? I will probably utilize ACF to create custom fields and custom post types which should be shared. (I looked into Formidable forms and they seem not suitable for this?) I am open tho anything that does the trick though.

Not critical but if possible I would also like to share comments on those posts between all sub domains. How can I achieve this?