Welcome to the forum! That’s a tough decision. If you can take a long trip with the raptors aggressive suspension, then i can’t imagine the AT4 would be any worse. From my understanding the AT4 and Denali both have similar seats and you can still get the AT4 with the technology package. On the other hand the Denali’s suspension is way more comfortable (not sure how the magna ride holds up with off roading), but it is still a capable truck with 4wd (just not as capable as the AT4). I feel like the AT4 is a good medium between the two since you do some light off roading, plus it’s nice to have the off road features just in case. As for the shocks i can’t imagine it would void your warranty, but you’ll have to ask your local dealer on their input (certain dealers can be picky about those things).