Your going to be seriously overweight with a slide out. Dry weights are useless for the most part. I have an 8 1/2 foot non slide camper on a Ford F 350 long bed crew cab diesel. I am 500 lbs over my GVWR. However I am almost 300 lbs under my rear axle weight, and even more underweight on the rear tires.
My Truck has 4400 lbs of capacity. That is way more than your Chevy, and I am still overweight. Air conditioners , generators dual batteries , dual propane tanks etc add a lot of weight. Not to mention your gear and food etc.
You would be best served to stick with a simple 8 1/2 foot non slide model. You will still be massively overweight on your GVWR but probably just under your rear axle rating.
I would steer clear of the Adventurer models. They are poorly built in my opinion, but to each his own. The North Stars are well built but seriously lack some of the nicer creature comforts like a real face to face dinette, and a one piece shower with a real door, outside vent etc.
Truck campers are costly. Most people like to gloss over the little stuff like Tork Lift frame mounted tie downs tork lift stable loads solar panels second batteries rubber mats etc. These things will add a few thousand dollars to an already expensive purchase, not to mention insurance costs etc.
Just keeping it real. If you are looking to buy new, you will most likely be well over 30 grand when all is said and done.
Good luck.