RE: slug hunting
The choice of slugs will probably be dependant on what type of a barrel you have (rifled, smoothbore).
Pretty much any reputable scope maker (Nikon, Leupold, etc, etc) with a low power and a long eye relief will work for you. Personally I do not like red dots, but I have quite a few friends who swear by them. Eotech has been really popular lately.