+1 for the CX4 Storm. I've shot it and the S2k quite a bit. The S2k did not run as reliably and I did not like the location of the charging handle - very hard to use especially under stress. I also don't think it comes with rails. Once you buy those, you are most of the way to a Storm.
Also +1 on any shotgun reccomendations larger than .410. I will disagree that a pump is simpler than a semi-auto. I think a quality semi is actually easier to use and, under stress, you don't have to worry about pumping or short stroking.
Also +1 on any shotgun reccomendations larger than .410. I will disagree that a pump is simpler than a semi-auto. I think a quality semi is actually easier to use and, under stress, you don't have to worry about pumping or short stroking.