If your slide is already cut to 15 degrees you have no problem installing the new style LCI extractor. Be sure to also install the LCI spring loaded bearing. See the factory & LWD extractors here: http://www.lonewolfdist.com/Search.aspx?TERM=lwd-1899
If your serial number begins with an "E" there was a recall regarding weak frame rails. I wouldn’t worry about it. If the rail breaks the gun will still function and you will discover it is broken when you disassemble it. The factory will warrantee it so no worries!
If you want a Gen3 gun sell the one you have and purchase it straight out. I have yet to see a kit that adds a rail and looks anything better than something stapled, glued or bolted on. You will not be happy, I guarantee it.