Here's a disconnect that can be mounted under the hood with the proper size cables, and it has a removable key. This can also serve as an anti-theft device as well as preventing self-discharge of the battery.

http://www.summitracing.com/parts/pco-5575pt/overview/

Always use a disconnect with plenty of current capacity. The cheap 100-amp ones will not carry starter current effectively.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!