These three :

109003
109203
109303

I looked at the spec sheets but couldn't figure out the differences. I am thinking it is either the trigger, mag safety or internal lock, but I really haven't a clue. I am wanting a 40c with the Novak Lo-Mount Night sights like my other 3 M&P 40's and a local shop has the 109303 for $475 out the door, $30 cheaper than the other two, and it got me to wondering. He said his distributor didn't list any with Novak NS at the moment. So I ordered it after making sure it didn't have the internal lock, mag safety or the heavy MA compliant trigger.

Now where to find the best deal installed on the Novak NS? Any recommendations on where to send it? Anyone local in DFW I can walk in and out and have them installed?

Thanks in advance