I'm not much of a shotgun guy, but I like the W1200 more, cause more bullets, and not much slower then the automatic.
As for perks, I use RDS, 3xfrag, stopping power, and steady aim.
Changing them up to Grip, bandolier, sleight of hand, and extreme conditioning may be better for some people, or mix and match each of them (3xfrag, sleight of hand, and steady aim for instance).
I don't use bandolier as I am never alive long enough to need it, but I pretty much just use the shotgun on shipment. Since it's such a small level it's easy to get the kills. I can get about 2/3 - 3/4 of the kill challenge done in each match with the shotgun (I know, other people can get more but this is me talking

). Plus you get a good chance to try it out a lot...