Thanks for the info gr7070.  I've got the SDM red one inbound from Midway, today.  I went ahead with the .250 height for the SDM as that seems the closest to the height of my factory front sight.  I wish S&W would stamp the height on their sights to remove any chance for error.

 I'm just going to take a strip of fine emery cloth and round off the sharp edges of my trigger.  It would take a lot of grinding with a Dremel tool to take off all the serrations so I'll just try the light buff of the trigger edges first. 

Scott