Circling back around now that I've wrapped up the install. I ended up with the AVH-X5800BHS and I'm stoked on it. It took a little getting used to since I've never been a huge fan of aftermarket units whose UI doesn't flow as well as we've all grown so accustomed with smartphones these days, but in terms of functionality, it pretty much does everything I could possibly ask. I used the PAC RP5-GM11 to keep steering wheel control and keep integration simple. I also ran a video line to the rear drop down screen for my son, and added a reverse cam. Because I wanted to retain the aux audio input (3.5mm jack) and USB connectivity to the head unit, I bought a generic 3.5mm/USB combo receptacle to replace the cigarette lighter. As for the iPhone integration and mirroring, I bought a little HDMI to RCA unit off of Amazon and then tied that into an Apple lightning to HDMI adapter. Picture quality is definitely lacking, but considering the legit alternatives were waaaay more expensive, and I really only need video playback for reference (i.e. maps) or for the passengers, I couldn't justify anything more. Since both the digital to analog converter and the lightning adapter need power, I just pulled the now unused cigarette lighter into the void under my center console. I had an old 2 USB car charger that I plugged into the dangling cig lighter, and then run the power to the converter and lightning adapter. This way I didn't have to cut/splice any wires, and I didn't have to tie up the only USB port on the head unit for power. This also leaves the second cig lighter available for road trips when I want to plug in my radar detector. Oh, and I also installed a parking brake bypass so I don't have to mess with that annoying warning that won't let you use video playback in motion. Lastly, I replaced the old battery, which was giving me issues, with a new AGM.
This took quite a bit of thought and planning to maximize functionality, but now that it's all set up and working properly, I couldn't be happier. I'm a stickler for keeping things clean so I hid everything and replaced anything visible with parts that look like OEM. The convenience now is at level 10!