I want to do the same thing at my house...someday!  The only advice I can give is that I outline my frames on newspaper and cut them out, then poke a hole through the paper where the nail needs to be and then put the paper on the wall first, use it to pound my nail and then hang my picture.  This way, you can get the spacing right, get it straight, etc.  because you can easily move it around.  By the looks of your wall, course, you seem to know this already!  Looks great and I love the word art. 
ps--I would do a third row! =)