ListView column help (How to autosize, align content and add column lines?)

<ListView x:Name="ChatterListView" Grid.Row="1" ItemsSource="{Binding Source={StaticResource ChattersSort}}" HorizontalAlignment="Stretch">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Name" Width="Auto" DisplayMemberBinding="{Binding Username}"/>

            <GridViewColumn Header="Voice" Width="Auto">
                <GridViewColumn.CellTemplate>
                    <DataTemplate>
                        <Grid>
                            <ComboBox ItemsSource="{Binding DataContext.Voices, RelativeSource={RelativeSource AncestorType=Window}}"
                                      SelectedItem="{Binding Voice, Mode=TwoWay}"
                                      DisplayMemberPath="Name" Width="Auto" />
                        </Grid>
                    </DataTemplate>
                </GridViewColumn.CellTemplate>
            </GridViewColumn>

            <GridViewColumn Header="Enabled" Width="75">
                <GridViewColumn.CellTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <CheckBox IsChecked="{Binding TTSEnabled, Mode=TwoWay}" Unchecked="ChatterCheckBox_Unchecked" Checked="ChatterCheckBox_Checked"/>
                        </StackPanel>
                    </DataTemplate>
                </GridViewColumn.CellTemplate>
            </GridViewColumn>
        </GridView>
    </ListView.View>
</ListView>