I've outfitted my 18 Silverado with the following:
- Simple isolator and second battery
- Basic tools
- Tarps, tie downs
- Additional lights front and back
- Onboard air from Viair
- Camper shell from ARE
- Decked drawer system with tools, camping and cooking gear
- 4 inch memory foam on top of Decked drawers, covered so it is a very comfy bed
- raingear, extra clothes/boots
- hygiene kit
- Water container - 7gal
- Jerry Can
- Full sized spare
- Comms (BaoFeng UV5Rs, chargers, etc...)
- Under seat safe that can hold a long gun and other valuables
- Paper maps
- Chargers and cords, mount for pretty much any USB-based charging
- Bucket for when nature calls
When I go camping, I also put a hitch-mounted platform on the back to carry my cooler.
I know you're not traveling all the time and camping....but consider what I'm trying to cover with each of those items.
You might want to consider a second battery - maybe a portable one you can add only when you go on trips. Those little power packs die and usually you are paying for other junkie stuff like a weak light and trashy compressor. Go with something that is pure power related.
Go on Youtube and check out "Minnkota boat battery case"...it is an enclosure that you can put a battery in and it has USB ports, 12v ports, etc... You can use a little battery tender in your garage and just take it out for trips.
Happy to answer any questions....