Looks like the total quantity of sugar in each bottle is 384 g or 1bout 13.54 oz . This is equivalent to a starting gravity of 1.033 and that is a potential ABV of 4.4% which is fine for a cider. A simple recipe might be to pitch 71B yeast. That said, I would be a little concerned about whether there was really enough nutrients in the juice for the yeast. So I would add nutrients. I would also want to add pectic enzyme about 12 hours before I pitch the yeast. That will help clarify the cider by breaking down the pectins that are in apple juice. Whether you add other flavors is up to you but you might consider adding a 2 inch piece of cinnamon to the secondary and allow the alcohol in the secondary to extract the flavor. You might dry hop with Citra or Nelson Sauvin hops (perhaps 1/2 oz per gallon of cider - again, I would add this to the secondary.
One way to increase the sugar content is to reduce the water content by freezing the juice and then collecting the frozen juice as it gently thaws. The first gallon you collect from BOTH gallon containers will have just about all the sugar so the gravity will then be about 1.066 (all the sugars will be coming from the juice)... but you will have only 1 gallon to ferment (I would actually aim for about 2/3 of a gallon of thawed juice)...