My assumption is you just need to remove the ceiling drywall, kill the mold, replace drywall. Not a particularly difficult job as long as the damage isn't severe.So I should still have a restoration company do this and just go with the one that has a more conservative approach? I'm assuming there isn't another type of company that can handle this work...
Wide variety of Restoration companies. You don't need a fancy one so stay towards the conservative side of the estimates. Definitely use one that has experience with mold. Really, most handymen or handywomen can do it - if they know how to properly treat the mold. Sounds like you'll need a plumber too - which might be part of the restoration services.
It is still going to cost you, that's unavoidable unless you're a capable DIY'er.