installing a cutoff switch

I just had to replace the 12V distribution panel on my '01 Tradewinds DP and now have discovered that I have a major battery drain which seems to be before the cutoff switch and really don't want to get the mobile tech out again. I am thinking about getting a regular marine cutoff switch and installing that to totally cut off the power. I am not worried about the alarm as I already had to disconnect that. There are two ways to connect these, one is to cut the cable and install connectors on each of the cut ends and the other is to get a post connector and not have to worry about cutting that big piece of copper cable and pressing new ends on it.
So I'm looking for advice on this from folks that have done this.