Firestick's seem to be the most popular with the Jeep CB crowd.All you need:
FireStik FL3-B Three Foot FireFly Antenna With Tuneable Tip (Black) https://www.amazon.com/dp/B005AUJXLM/ref=cm_sw_r_awd_j.l-ub138F80R
Good info! I am going to mount mine on the spare and buy the 5 foot Firestik. That should get me a decent distance above the roofline.How to tune your firestik: Setting the SWR of Your Antenna© - Firestik® Antenna Company
To do that you'll need a SWR meter and a patch cable. That will run you between $10-20.
Don't worry too much about manking a ground plane. The only really good ground plane on a Jeep is the hood, and you don't want your antenna in the middle of your hood.
Just use a commercially available antenna mount and follow the directions exactly when you install it. Pay close attention to the part about grounding the mount. All of the mounts made specifically for Jeeps are "good enough". I would avoid a generic "vehicle" mount unless you want to research a good place to put it.