Previoiusly I was considering the Leupold VX-3 1.5-5x20mm with 4.4" ER, 9.3 oz, and 9.5" long; mainly for the compact size and light weight.
I think that's plenty for an 1100, I only have a 1.5x4 and it's more than enough, If I can see it where I hunt I can hit it. Granted my furthest shot was only 110 yds but most are 85. Actually I stopped using my slug guns a few years ago and switched to a muzzy with a 3x9 .