I was trying to do a same update from Lion ( 10.7) and after many hours of collecting info, it looks as you can only go to Yosemite.
I really wanted to have 10.9, but as far as I know it is not possible. At least not via Apple.I could be wrong, of course.
BTW, I am running N7 on W7/64 and happy. ( yeah…the known bugs beside )
My Avid PT therefore will be abandoned .
best of luck