Is this the kit your refferring to?
TeraFlex JK 2.5 inch Lift Kit, W/out Shocks
If so, it will come with everything to get you started minus the shocks and the exhaust spacers, assuming your new JK is a 2013. Also, to the question of what you can add to it, well, alot! You can always add to a lift and make it better. It depends on how much you would like to add and what you are trying to accomplish. A adjustable front track bar and adjustable front lower control arms is nice to have!
Here is a compribale kit from Rock Krawler that has these two options:
Rock Krawler JK 2.5 Flex System
I am sure you will have a few questions though. If there is anything we can do to help, please let us know! We carry a ton of different lifts and can help you select the right one for you and your needs. Feel free to PM, email, or call us at anytime!