GMC Yukon rear end sagging - anyone tried this place for shocks?

My 2012 Yukon Denali has been feeling like a boat in the rear lately, especially over speed bumps near my kids’ school. I’m pretty sure the rear shocks are shot because it also sags a bit when I tow my small trailer. The dealer quoted me something ridiculous, so I’ve been searching online and came across https://suspensionrepairdubai.ae/gmc-shock-absorber-replacement/ which seems to focus specifically on GMC trucks and SUVs. Has anyone here actually used a shop that knows these autoride systems well? I’m worried about messing up the electronic suspension because I’ve heard horror stories about shops that don’t recalibrate things properly. Not looking for the cheapest option, just fair pricing and someone who won’t break my air lines or sensors. Any real experiences would help a lot. Thanks.