I've usually got too much stuff in the bed of the trucks to worry about trying to sleep in the bed. Hay bales, water jugs, chain saw, shovel and other tools that I don't want to take time to remove. So we either sleep in the gooseneck or pitch a tent.
Four horses that can each drink 10 gallons a day, go through a lot of water. I got some 15 gallon mini drums from a local dairy farmer. The disinfectant that they run through the milker comes in these and he throws a couple away each month. 15 gallons is about 120lbs. So they are heavy, but a person can move them if needed. At camp, I roll one to the tail gate and open the valve. Best of all they are free. Even if I don't need the water for the horses, I still use these for water for me to bath in, wash dishes etc. And I like to have water in the truck in case we get stuck in traffic on a hot summer day. It's only happened once to me, But sitting 3 hours on the freeway in 100* temps because of a traffic accident up ahead will make you a believer.
We use the electric fences a lot in the wilderness. But we always highline at night. Too many mornings I've gotten up to find that elk have run through the meadow and knocked down the hot wire. I also carry hobbles on my saddle, We often hobble the horses while we take a lunch break.
I often use my horses rain sheets as covers for my pack saddles. Keeps my gear dry on the ride in and helps the horses ward off mountain chills at night. I also use a canvas mantee as a drop cloth, to cover saddles at night, and even on a few occassion to dry off after a dip in mountain lake.
I keep one of those LED headlamps in my gear. They don't throw a strong beam for a long distance. But they do provide some light and the batteries last 300-400 hours. So even if I accidently leave it on or it gets switched on in the pack, it won't go dead in a few hours. These are not bright enough to go find a lost horse, But they are enough light to adjust a highline in the middle of the night, to gather some firewood after dark, or see branches before they hit you in face if you ride after dark.
I always pack a lightweight rain jacket. At 10,000 foot elevation, Getting wet, means getting hypothermic and mountain thundershowers can slip in anyday in the high country. I often cut off the leg from a pair of deniem blue jeans. I then pull the slicker through the leg. Then tie it behind the cantle. The deniem protects the lighter nylon from getting caught on or torn by thorns as your ride through the brambles or oak brush.