Cabin,
You don't have to stick with a shotgun scope, but one think that maybe important to you is eye relief. Another thing to consider is the average distance you will be shooting. Shotgun scopes typically have a parallex of 50 yards, where a rifle scope will have a parallex of 100-150 yards, depending on brand. We have a lot of people that buy the Bushnell Elite 3200 2-7x32 for their shotgun. Actually I know a lot of people don't care for them, but the Weaver Classic shotgun scope is great little scope. Very clear and bright.