I don't see, or maybe I missed it, how heavy your trailer is and amount of people/ cargo?
This is just my opinion and I'm a chevy guy too. I owned a 2007 denali as my last tow rig and absolutely hated that thing. Constantly in and out of the shop and literally falling apart. I wont go into all the details but it had electrical issues as well.
So.....if you need a 3/4 ton suburban still I would go back one body style. I have owned 2 2000-2006 suburbans, both with way more miles and abuse on them than the 2007, and they are great vehicles. Tires and batteries is all I worry about. I currently have an 05 3/4 ton burb with the 8.1. Hands down the very best truck I have ever owned. Just my 2 cents.