Battery switch ?

[sidelock]

I need to install a battery switch in my 18SF since it does not have one & I'm undecided on where to locate it. I would prefer to install it in the center console but that would leave the tilt switch on the motor live/active since the two heavy leads from the motor are hooked directly to the battery terminals. The other choice would be to install it in the rear/transom battery compartment where the cranking battery is & hook it up between the motor & the battery connection & that would also address the tilt switch issue . Which way should it be ? Does it boil down to personal preference/choice or is there a right/wrong way to install it ? Should the switch shut the power off to the entire boat including the tilt switch or should the tilt switch be left active for practical/other reasons ?