I'd suggest a tent over a hammock too. For rough routes google the perambulation of the moor. The fringes away from the more remote north and south moor are also very well worth a visit. You haven't stated when you plan to go but check the range times. Okehampton isn't usually too much of an issue as you can come down to the east from Okehampton. In any event they don't use em at weekends so you can jiggle your schedule to fit. I'm propbably going from Okehampton to Princetown on Wednesday/Thurs but am having to go further east as I move south to avoid Merrivale ranges. It's easy to drop off the moor into a village or town for food so you don't need to carry a weeks worth unless you really want too. Enjoy.