Lotus Notes into SharePoint without diminishing the original data and objects.

We are planning to transform Lotus Notes to SharePoint. We are fully aware that the process entails a rigorous undertaking. In order for us to have a good grasp about this, we are looking for some advice from people who have the knowledge and experience of the entire transformation process.
We are aiming to transform Lotus Notes into SharePoint without diminishing the original data and objects. We are particularly interested on what conversion tool to be used. An expert insight on this matter would be very much appreciated.
