The Secretary of State websites do not provide operating agreements - all you can get from the state websites are the articles of organization to officially file the LLC and bring it into existence. The operating agreement is a different document kept with the company's internal records (is not provided by the state and is never filed with the state).
As for using an attorney vs a doc filing service, since single-member LLCs do not need to address issues pertaining to multiple owners, most people are just fine using the less expensive doc services instead of a lawyer (and, as you noted, often lawyers indeed just use the services' documents and then jack up the price to you).
Note that doc filing services' operating agreements are generic, so you might want to use the service's operating agreement as a template, then, before signing it, run it by a lawyer (chepaer than having them draft it "from scratch") in case you need to alter any provisions specific to your situation and the laws of your state.
In which state are you forming your LLC? I can provide the laws pertaining to operating agreements in your state for you.
Good luck Bienes.