I did an Alpine WRA restyle unit in mine- it comes with the head unit, dash brackets to fit the double-DIN radio into the wider JK dash opening, a new rear radio support, a Maestro unit (that allows use of the steering wheel controls and interfaces with CanBus), as well as a custom wiring harness that makes it plug & play. While mine is an older version (i207-WRA), they have newer current models. They aren't cheap, but I have been loving mine. I added a plug & play Alpine back up cam at the same time that is a single connection to the head unit rather than something that needs to be wired into +12V and a reverse trigger. I am an IOS guy, so while my Alpine has Android Auto, I haven't used that aspect of it.
If you want to source your own dash kit, a Maestro and use an aftermarket wire harness, you aren't limited to a kit- practically any double-DIN that is Maestro compatible will work. There are other CanBus interfaces as well, but Maestro may be the most popular. You'll probably have to modify the rear radio support when installing most aftermarket head units.
Installing in a JK is more complicated than things were from the 70's to early 2000's as they have a degree of integration with the Jeep's onboard computer, but it isn't rocket science. You have to program the Maestro via PC (or now for Mac also) to match the Jeep and your chosen new head unit, pop off some trim on the dash, header and a-piller. Run a new microphone for hands free and a new GPS antenna, connect it all and button things up.