One data entry form will suffice as long as the only requirement is to direct which sheets gets the data. I would use a checkbox control to direct which sheet receives the data.

You will need to upload your workbook with the form if you need help with the code.

Basic code example:
Private Sub CommandButton1_Click()

    Select Case Me.CheckBox1.Value
        Case True
            'code to write to sheet1
        Case False
            'code to write to sheet2
    End Select

End Sub