figured out the XAML to get rid of selection style.. not ideal, but close enough..
<Style x:Key="CellStyle" TargetType="{x:Type DataGridCell}">
<Setter Property="Foreground" Value="Black" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Background" Value="{x:Null}" />
<Setter Property="BorderBrush" Value="{x:Null}" />
</Trigger>
</Style.Triggers>
</Style>