I hiked the FT back in 07'. Granted, there are a couple of choices to make in regards to loops and things may have changed since I hiked it, but I used a hammock for the entirety and didn't have any problems finding a place to hang. I also didn't really use the suggestions as to where to camp, so that may factor in as well.
Worry more about your feet in the southern end. Those roadwalks will melt the soles of your shoes faster than you'd ever imagine.