Hi, I worked in a company where building Business Models was one of the prime activities, I am referring to Baan ERP Company (now part of Infor) if you have heard of. We used DEM Modeller to make these models, of which I have quite a good knowledge. I have also experience making Wire frames using MS Vision, I believe this is relevant also as this project is asking for making BP diagrams in MS Visio. I am assuming that we are dealing with a Small/medium Business, in making this quote.
I can help with many other things if and when they could become necessary as a part of Business Modelling. Please let me know your interests via a message. Thanks.