Everything that you need, minus the dampening material, comes in the kit.
The crossover must be point to point wired but is easy to assemble. I recently posted a sticky on how to assemble crossovers. You see it at the top of the threads in my circle.
Here is an assembled LS-9 network.

There is an adjustable bass management system that will allow quite a bit of flexibility in the bottom end. However, room treatment, tube traps, etc are recommended and will really be helpful across the back wall (behind the speakers).
LS-4's will have good off axis response in the horizontal plane but limited vertical dispersion due to it's short line length. So one must be seated with the ear near the middle of the line to get the proper balance.