integrated search function on a new website

We are creating a new website that will be have a lot of articles about a single topic area. We would like to have a guru help us find/design/create the best search user interface. we would like the guru to review our needs and then recommend the best search solution ideally showing us examples of the different options that are used by existing websites. We need something better than simple free word search systems like Google site search. ***Please quote ONLY on helping us determine the best search system. DO NOT quote on developing the entire site or doing any programming**************