a easy cheap way ive used to do what you want is to use a marine type terminal on the batt.they are the ones with the stud sticking out of them and usually come with a wing nut on the stud. i cut the regular terminal off the cable and solder on a round copper eye on it. takes just seconds to lift the hood and unscrew the wing nut and lift off the cable.cost prob about 5 buks for the terminal and the eye.
my local parts store sells a blade type switch terminal made of copper. it mounts on the batt and has another post you hook cable too.they work ok but must be kept clean. vibration can cause probs with them but they are usually good. you simply lift hood and lift the blade straight up to dissconnect the batt.
if you want the ultimate disconnect switch, use a caterpillar main disconnect switch off a older caterpillar dozer or grader.they never mess up, are made heavy duty and take vibration well.you mite find one at a local heavy equipment salvage yard. i would mount it on the fender near the batt and run a cable to it from the batt and then another cable to your starter.
let us know what yu choose?