Philip,
No, you don't need to map the sub-classed BOs, if you're doing it like Trent suggested. Because the report BO is sub-classed from the main BO, it will have all the functionality of that main BO. Also, if you change the underlying table, you only need to remap the main BO. All the sub-classed BOs will immediately get the changes.
The sub-classed BO just ensures that if you need to do something specific for a report, you can do it in one class and not break other reports. It also ensures that you don't have some huge, overly complex BO trying to handle everything.
As to not having these within the toolbox, you can use the ToolboxItemAttribute.
// C#
[ToolboxItem(false)]
public class PatientBO
' VB
<ToolboxItem(false)> _
Public Class PatientBO
You might want them in the toolbox though, if you will be dropping them on forms.