How to store selected value from DataGridViewComboBoxColumn?

Question

VB.NET 2008 .NET 3.5

Using WinForms.

I have a class that is bound to a DataGridView through a BindingSource. This class contains a List as one of it's properties. The List contains another custom class. Both classes are part of an automated shipping program:

Class OrderShipment
    Public Property OrderID as String
       Get
       Set
    End Property

    Public Property AvailableBoxes as List(of Boxes)
       Get
       Set
    End Property

End Class

I have the List "AvailableBoxes" databound to a DataGridViewComboBoxColumn. The user will select a "Box" from the list.

I need to store the selected "Box" in the OrderShipment class. I have two solutions to this, but am looking for other suggestions/improvements:

1) Handle the DataGridView.EditingControlShowing Event. Evidently this is the only way to get access to the ComboBox Events. You have to Handle the EditingControlShowing Event, cast to a ComboBox, then you have access to the regular ComboBox Events. The selected value could be stored in another property inside OrderShipments.

2) Same as #1, except create a "Selected as Boolean" property for the "Boxes" Class. Set this property to true instead of creating a new property in OrderShipments.

Both of my solutions require the funky Event Handling required to get DataGridViewComboBox Events. The BindingSource obviously knows which Item from "AvailableBoxes" is selected. Is there a better way to set/store the selected value?