Here on www.avvo.com you can find a number of attorneys under the lawyer search tab. You can search by the type of law the attorney practices (e.g. business) and then view how they charge (fixed fee, hourly, etc.). Asking a question on this forum won't be as efficient as looking in the lawyer search section.
I am sorry to tell you that most attorneys would not feel comfortable sending out letters under their signature without knowing the underlying facts, which does involve some research and thus time investment. I am not saying you won't find someone, but you should have realistic expectations. You should feel free to search on Avvo for business attorneys. Also, the best referrals are generally going to be from people you know, so ask other business people you know, particularly others in the same line of work, with whom they work.