Look at these two posts on the forum:
2012-13 Wrangler Aftermarket Stereo Install Write-up
My headunit is a Pioneer AVH-2500BT. I bought it from Crutchfield. The reason I bought from them was their customer service and knowledge. It was $350 plus $75 for the wiring harness that allows you to use your steering wheel controls. Crutchfield also gives you the Metra side pieces and antenna cables for free. I could have saved by going Amazon, but I wanted their service if I had issues with the installation (I'm 55 and have not installed stereo in a car for at least 30 years). I spent $425 on the headunit and the harness. A local shop wanted $900 for the headunit and installation.
I read a lot of reviews on various headunits on Amazon, Crutchfield, and other sales sites. It came down to the pioneer or kenwood. You can spend anywhere from $150 to $1000 on a headunit. Depends on what you want it to do.
I have $585 total in this including the cost of the speakers (Kicker 77KICK10). A lot of people here use kickers or Polks. I did nothing to the factory amp. It is worth it to me. The factory unit really sucks. It is easy to install with the directions you will find on the forum. Just search headunit. Lots of knowledgable people on here.