cutoff

I would like to relocate my battery to the rear of my 5.0 hatch. I know it needs to have a cut off switch. What is the cheapest/easiest way to set this up? Also, I want a kill switch, can this switch double as a kill switch?

I recently took off my cats and put on my offraod hpipe, brand new shorty headers and plugged the holes to my smog pump, but still the car stalls 10mins into driving to work. The wierd thing is, it stalls completely then when i start it back up (on the side of the highway) it will run perfect...