I am wanting to buy a shot gun. I am steering tward a auto loader preferibly the 11-87. I am wanting to use it from anything to duck hunting to slugs for deer hunting. What legth of barrel would be a good legth or should I get different barrels?

I love my 11-87. It's an awesome all around gun. You can use the barrel that comes on it for pretty much anything depending on your choke combination. And there's also two different rifled barrels you can get for it. One with rifle sights and the other with a scope mount. I'm definitely very satisfied with mine.