Welcome to the Forum from NH.
Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.
I hope that you will become a participating member in the Forum's discussions.
Since you have the Denali, I am assuming that you have a Bose audio system. There are folks here on the Forum who have changed out only the head unit on their Bose systems, and they will chime in. I am not a fan of Bose systems, so I ripped out the entire Bose system and installed a complete aftermarket system.
Regarding head unit recommendations, lots of folks here on the Forum like Kenwood and Pioneer head units, and they will have all of the features that you are looking for at various price points. I recommend that you go to the Crutchfield web site and look at the head units that are compatible with your truck. Then, you will see the various head units and their features at the various price points.