I recently bought a battery for my setup while away from the house, my battery needed to run a laptop the mount and my cameras.
I did a bit of research and found that you need to get deepcycle batteries to run astro gear. The jump starter you linked will do the job, but you will kill the battery in it very quickly.
normal batteries are made to put out a large current for a short period of time to start the car, then the alternater takes over and runs all of the cars electric gear during the drive ( radio, computer ect ). If you use a car battery with your gear you will trickle discharge it and then charge it back up presumably. The fact is that they are not made to be discharged very much.
I bought a deep cycle battery and a suitable charger from super cheap auto and thus far it has worked a treat.
http://www.supercheapauto.com.au/onl...31#Description
http://www.supercheapauto.com.au/onl...63#Description
For a visual setup ( or just a less power consuming setup) you could use a lower capacity battery and a smaller charger.