I've got the Premier 164' not permanent 48" and it is challenging enough to move by myself. 4000' long? I'm sure you've considered which charger you need for that. You are usually pretty thorough and think things through.
I'm not sure how permanent you want it to be. Have you considered regular fencing with three hot wires, one real low, one a foot up, and one at the top? It might be more practical for what you want to do? Maybe permanently fence separate paddocks and move them from one to another? The charger to handle poultry netting at that length would be my concern, but I have not looked into that.
No, I don't know of any sources for longer lengths.
I don't move mine at night, but I don't have nearly the number of chickens you do. I just leave them locked in the run, take the netting down, mow the new route to get the grass and weeds as low as I can get them along the new route, and put the netting up. Mine spend every night in the permanent coop and my paddock areas can be accessed from my permanent run and coop. Different conditions for different people. I don't know what the permanent Premier netting is like, but my concern with mine about moving it at night would be snags.