For the last week, I’ve been asking for advice to wire a three-way switch with two lights in between.  The responses I received were great!  But, in the future, it is much easier to tell someone that you should not worry about any number of fixtures other than the first light.  Every electrical book shows multitudes of diagrams with one fixture but I have yet to see one that explains what to do to add more fixtures.  So, wire your three-ways like one of the diagrams in a book with one fixture.  Then, simply run 14/2 wire from the first light to the second light.  It doesn’t need to be that complicated.