I'm going to be getting a 920XT soonish, so depending on how imminently you need it, I could send you my old 310 so that you could get an idea of what features you might or might not need. Let me know.
I would say forget the specific plans, and just do more of what you enjoy, you're more likely to stick to it that way. I think ultras are more about lifestyle than schedules. But that might just be me. Enjoy trotting along in the countryside and don't think of it as a chore, and you'll be right.
Yeah, I do the charger thing in my hundos, but anything that takes away that faffing around is a great help, especially when I'm at the stage when opening a gate is like the krypton factor, and stepping up a curb is like an obstacle race.