personally, I would never use a slug for a home defense round. Overkill, for a lack of a better word. I would use 00 for home defense in my Rem 870 tactical if I wanted to, but I prefer my 45 any day (Kimber Ultra Covert II) especially since it has a laser grip and shoots perfect. Just my choice though, as a 45 allows me to move silently, stay concealed and able to take quick action. Nothing like getting lit up with a laser on your chest. Very intimidating. Just like hearing the sound of a slide go into battery or the sound of a pump shotgun being armed.
For what's is worth though, no gun will be good for home defense if a person doesn't train and practice with it. That means you should be able to manipulate the weapon in darkness and the light, shooting it from various positions simulating areas in your house. What you do in practice will carry over into a real life situation. Being a retird LEO, I've understood that for years and use it when I teach a tactical carry class out here for those with their ccw. We also teach the use of shotguns for home defense during the same class to show limitations and advantages to each type of weapon. It's very eye opening.
As for what ammo to use, try several options listed in this thread. Do your own tests or see what others have found from their research. Every type of ammo I use whether it's for carry or hunting, I did my own research. Hornady Critical Defense ammo is good stuff. Either #4 or 00 is good to go for home defense. Just remember, there are 9 pellets in a 00 shell. That's 9 decent sized pellets to encapitate the threat.