I used to go further north to Chester and thought it was good there too but since my brother moved to PA a decade ago, I haven't really bike it so I don't know conditions. Same thing for the sourthern leg. My memory is that the road is decent. I will find out the 15 or so miles north of Hammonton in a couple weeks on my way to FL but might not be able to update here.
Unless you really want 206, I'd switch over to County (?) 601 from S Hillsborough to Princeton. You'll end up at a light at 206 after it turns in Princeton. 601 shoulders are not as good but unless you're doing this in rush hour, it has much less traffic. The continual noise on 206 has started to bother me. And rush hour seems to start around 3:30.
Note that a couple miles further, where 206 and 130 meet, it will be a little tricky and busy but once they split again a little later, 206 quickly becomes better.
I have camped in Atsion. My recollection is that it is 10-15. Has water and showers.