Deciding on what kind of rig you want to build it to be is the first order of business. So you don't spend money on things that will not help you. Curt is right if you are going to take it rock crawling rocker guards are a must and will save the sides of your Jeep from rock rash. The tires you have are 'ok' to start with. I had them on my Jeep when it was stock. They will get you by until you are ready to lift your Jeep and get a bigger set. Unless it is going to be a long time till you plan on doing that I would not waist your money on tires till you can fit 33' or above.
EBay is good just be careful, sometimes it is worth more money for a warranty. There are lots of great places to buy from. I have heard good things from North Ridge 4x4,
http://www.quadratec.com/, is good as is
www.4wheelparts.com/.
The best thing to do now is take it out and get used to driving it the way it is. It will be hard and you will bang up your skid plates a bit but you will learn how to read lines better than most of the people that bought a rig and then moded it right away. You will also learn good tire placement techniques. It will also help you decide what mods to start with. You will see what you need and plan accordingly.
If you want to go out to some easy trails I would be happy to go with you. And I am sure most people on this forum would be more than happy to go with you as well.
Hope to see you on the trail.
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