You shouldn't need the Flashpaq for the stock configuration. Now if you plan on bigger tires etc before you go them you might want it or if your towing a trailer. You also didn't say which model you were getting or what lift size etc you want to go to after this road trip. Seats should be good, especially with all the stopping you plan on doing.
Make sure everything is mechanically sound before the trip. Specifically the brakes. You can spend 15 mins getting to 65+ if you had too, but when you need to stop, you NEED TO STOP! Get a CAI (AFe is good) and if you aren't going to go wild on a lift (requiring exhaust mods), when you get one, get a cat back exhaust before the trip (air in, air out sort thing).
Get security boxes and leave the damn thing unlocked. Also park it in plain view whenever possible. With an unlocked vehicle and in plain sight of everyone, thieves will assume the owner is close.
As far as Moab goes, get some quick disconnects and go for it in stock configuration. This way you will learn your vehicle, your driving abilities, and what if anything you want in a build up afterward. If you don't plan to go wild on lift/tires (so as to not be changing gears) and such when your trip is done, maybe throw in a couple of lunch box lockers (Aussie << my choice, Lock-Right, Spartan, etc). Very affordable, decent road manners, and you can do it in a few hours with standard tools in yours or a friend's driveway. Plus you should change the fluids and check the brakes anyway, being it is used, so you're half way there on the install as it is. This would open up a little more challenging terrain for you. Read a head-to-head article here about these lockers
. I am sure there are as many of these articles on the net as there are opinions here. Research it, if interested in this option, and make your choice.
Many many soft/bikini tops to choose from. Many people say to stay away from Smittybilt tops. Never used one personally. Rampage and Bestop are excellent choices for all there product line in this area.
If you want or need any help acquiring these or any products, send me a PM. Sounds like a fantastic trip and we DO expect pics during you're travels.