The Wrangler has been through three generations. They are designated as the YJ, TJ, and JK. I think those might have also been names of the Backstreet Boys.
The first generation YJ was sold from 1987 until 1995. It came with an I4 or I6 engine, and it was sold as either a convertible or a truck, both with 2 doors.
The TJ was sold from 1997 until 2006. It had most of the same features as the previous generation, but with coil spring suspension and round headlights to remind buyers of the CJ look. The TJ Rubicon is a special edition from this generation that is made for better offroad performance.
The JK has been sold since 2007. It is sold as a solid top SUV or a convertible. It now has an option for 4 doors. Transmission options are 4 speed automatic or 6 speed manual.
The new Wrangler Unlimited is like a stretch version of the Wrangler JK. It would compete in the same market as the Hummer H3.
These compact SUVs are everywhere. If you are looking to buy a used Wrangler, just open your eyes and look out the window, there's probably one turning around in your driveway right now. If there isn't, try looking on eBay.