Look at the sale stuff on Crutchfield.com. They have a ton of info and documentation for the installation of everything, include pretty much everything you need (the Maestro box is extra, but proper mounts/wiring/etc is all included), and will provide knowledgeable technical support for the life of the product. I got my Kenwood Android Auto receiver from them earlier this year to replace a dead factory headunit, and it was very straightforward (though I did have to basically take my whole dashboard apart, the instructions were clear and all of the parts fit without issue). If you want full plug-and-play, they'll even wire up the receiver's plug to the factory wiring harness plug kit for $25, and do a much better job than you probably would have done.
Wireless phone integration will be quite a bit costlier than a wired connection. Looking at their selection right now a wired receiver can be had for $250, while the least expensive wireless receiver is $370 (and wireless Android Auto only). Standalone GPS starts at $600.