I'm surprised you're able to dump in the pit toilets. Usually they frown on it because they then have to have them pumped out. A macerator would be the easiest for you. Is there a dump service that would come to you?
For fresh water - there's a gizmo called a 'water bladder' and I believe Camping World even sold them. If you have a truck, the large 'bladder' is put in it and you drive somewhere to fill it up. It holds a lot of water. I hope this gig is worth the trouble and perhaps cost that you'll endure. Good luck!
