Take your pick! I can't think of a vendor that dosen't have a platform capable of handling what you are requesting. Once you narrow to a specific vendor, price range, software package, etc someone can help you pick the appropriate processor family to suit your needs.
In regards to the Analog isolation, nearly everyone offers this. If you want more than that vendor has, Automation Direct and Phoenix Contact have opto-isolation modules that come in quite handy on ocassion.