I am very familiar with short section between the Philadelphia area and the Port Jervis, NY area as I try to ride some or all of it every year.
For obvious reasons, there is nothing in the way of camping on or near the route north from Conshohocken until you get to the Milford, NJ area. From Milford, you can cross the river into PA and head back south about 1.5 miles to Dogwood Haven Campground. (Most of that 1.5 miles can be done on a bike path.) The place is a bit dated, but the owner is very nice. Last year he was still giving cyclists a discount rate of $15, which is cheap for that area. Milford has good pizza and a surprisingly decent grocery store for a town of its size.
Heading north from there you won't find any campgrounds until you cross the river from Belvidere, NJ to Mt. Bethel, PA. Driftstone on the Delaware is between Mt. Bethel and Portland, PA. Never stayed there, but I know it's wildly expensive. Over $30/night and possibly as high as $40. There is a historic old hotel in Belvidere, but it's expensive. The town itself is worth a look see. There are many nicely renovated Victorian house on the streets around the large town square. Grab a sandwich from Skoogy's Deli on Greenwich St. (the other location doesn't have a bathroom) and have lunch in square.
The next camping spot on route is the campground at Worthington State Forest, which you pass right by a few miles after crossing the pedestrian bridge along I-80 from Delaware Water Gap, PA into NJ. Nice place along the river. $25/night for non-residents. If you stay there, ask for the group site with the bear locker. There are a decent number of bears in that part of the world, and they can get very big. Not too long ago someone bagged an 800+ lb. bear on the PA side of the river not that far away. You will need to go off route a very short distance into the center of Delaware Water Gap, PA for food. No grocery store, but there is a convenience store with some canned goods. There is also a diner, a pizza place, great bakery that has BBQ on certain days during certain times of the year as well as a couple of other nicer restaurants.
North from the Worthington campground there are no food sources on route until you hit Port Jervis, a distance of about 34 miles. There are water and bathrooms at Old Millbrook Village, which is about 9 miles from the campground. If you desperate for something to eat, when you get to Peters Valley Craft Center you can stay on CR 615/Bevans Road instead of starting the climb. About 2 miles down that road you will come to Layton, where there is a very good place called the Layton Country Store. It was closed for a while but recently reopened. I was there in October and the food was quite good. Hope they are able to make a go of it. Reverse course to Peters Valley Craft Center and continue on route. Or you can take CR 560 directly from Layton and then make a right onto to Old Mine Rd. and you will be back on the route. I caution against that as CR 560 always seems to have a fair amount of fast moving traffic.
Three or so miles before you cross the NY state line there are two campgrounds on the right side of CR 521. From what I have read, the first one you pass (Cedar Ridge) is a dump, assuming it's even still in business. The second one (Rockview Valley) is a little hickish, but o.k. Check their web site for opening dates.
It seems the full-service grocery store in Port Jervis is out business. If you cross the river into Matamoras, PA and head a but west on U.S. 6 there is a large grocery store (Price Chopper) on the right and just about any other service you could want. It's actually an interesting if you understand local economics. Taxes in NY and generally higher than in PA so people drive across the river from NY to PA to save money. Where it's particularly visible is with cigarettes. There are several tobacco outlets on the PA side of the river. Gas is the same way. There is one small station in Port Jervis but several of them in Matamoras as gas is noticeably cheaper in PA.
North of there, ACA changed the route some since I road home to Philly from Bar Harbor many years ago. I have the new map at home and will check to see how it compares to what I did. But in general, I would say that 60 miles/day is a reasonable number assuming you are in decent shape. The section from the bike trail in Conshohocken to New Hope, PA is not overly hilly, and there are no long, hard climbs. When you cross from New Hope into Lambertville, NJ, you can take the D&R Feeder Canal trail all the way to Frenchtown. That is basically flat. I recommend it as the surface is good and it's shaded. Also, NJ 29 has no shoulder between Lambertville and the north end of Stockton. If you find the trail boring, you can get back on NJ 29 at Bull's Island Recreation Area, where there are water and bathrooms. At that point, NJ 29 has a wide shoulder all the way to Frenchtown. The rest of the way up to Port Jervis has some ups and down and includes two steep climbs in the Delaware Water Gap National Recreation Area, neither of which is more than a mile. Outside of those and the mega-steep but very short "bump" out of Mt Bethel, PA a little ways after you cross the bridge from Belvidere, NJ, the climbing is not really arduous. The only bad traffic area is in and around Philipsburg, NJ. The section between P'Burg and Belvidere is a sheer delight. Very little traffic and pretty. And due to narrow, overhead railroad bridge passes, you don't get any trucks.
