I’m afraid professional liability seems to be one of those taboo subjects. Nobody ever wants to discuss it in specifics, unless related to a code or design potential and then only in vague terms.
From what little I’ve gathered over the years, you’re looking for a lawyer. I’ve been given the impression that most liability insurance providers either want to review your contracts or have certain things they want to see in them. That may be a good place to start – asking your insurer for local references, or at least references familiar with local law if they won’t do it themselves. Beyond that, a lawyer familiar with or specializing in design, construction, and contract law. Both firms I’ve worked for and been at least semi-familiar with the contract had them reviewed by lawyers though they took different approaches; one was a few standard phrases and that was it, the other was a Master-Spec like everything including the kitchen sink lettered section multi-page contract that could be edited down and tailored to a specific project.