Is there a way to change some of the pre-programmed fields?

Is there a way to change some of the pre-programmed fields?

In "Leads" there is a mandatory "Last Name" field which is not editable and the "First Name" field is also not editable. I need to have just one text field that I would call "Name(s) of Contact Person(s)" because we have multiple people that we work with from each of our Leads and this would be much easier than putting their names in Contacts. I would also need this field to map to the same field in Accounts so when our Leads are converted, the full list of names would transfer over all at once. Any advice?