2018 DCLB TRD OR Suspension upgrade question

Hi all,

I'm planning a 2 month roadtrip throughout the western US where I will be living and working out of my truck full time. This is my first time modifying the suspension of a truck and I've read through many posts on here, but am hoping for some advice on best options for my specific build type, intended usage of the truck, and budget. I've included details below -would greatly appreciate any help/opinions.

Background
- My girlfriend and I are taking a two month roadtrip throughout the western US and will be living and working out of the truck. We may stay at an airbnb or two along the way but will likely spend 90% of the trip living out of the truck. I currently have a cab-height camper shell and wooden platform built in the back for our camping trips. The wooden platform is made out of 3/4" plywood on 2x4's running widthwise in the two notches along the bedsides. We use 2 plastic bins beneath the bed for storage of our camp and recovery gear, so there is no wood drawer system. I will likely change the sleeping platform before the trip, however weight will stay very similar.
- The reason I'm looking to upgrade the suspension is because as the truck setup currently sits for our weekend/weeklong trips, there is a slight sag in the rear end due to the weight in the bed. I have bottomed out once or twice on 4x4 backroads previously (more on intended usage below). I'm concerned with extra weight from a rooftop carrier and some additional camp gear needed to work from the truck, the back end sag will be worse and affect driving performance, especially off road.

Truck
- My truck is a 2018 DCLB TRD Off Road and is currently stock, and my goal is to upgrade it for functionality and generally keep it as stock as possible. The only items I've added to the truck were a cab-height Leer camper shell and built out a simple wood platform w/ 3 inch foam mattress topper for camping. I'll be adding ditch lights before the trip, as I drive a lot of empty roads at night getting to and looking for campsites.
- Future Mods: None planned at the moment aside from the ditch lights

Intended Use
- I spend a lot of time driving BLM/Forest Service/National Parks roads when camping, and will be doing so for the two months throughout the west (likely Nevada, Utah, Idaho, Washington, Oregon, California). These roads are usually relatively well maintained 4x4 roads, with some occasionally rough spots. I have bottomed out a couple of times in the past due to poor route planning. I won't be doing any technical rock crawling.
- I drive a lot of highway/pavement miles to get to camp spots and parks, so highway performance and gas mileage are important.
- This truck is also my daily driver

Budget
- As usual, not looking to break the bank but want to upgrade the truck properly

Thank you in advance!

 

Any advice appreciated