I copped a great deal on a near new Remington 1100. Not tactical by any means but just as deadly. The single piece of advice that comes to my mind about shooting a shotgun is to hold the stock tight against your shoulder. I shot skeet for a few years and the first weeks of shooting taught me that little lesson. Amazing how a big strong guy can turn so many shades of black/purple/green over a large area of his shoulder!
My goal is a Mossberg 930. I like the semi-auto's even though they are a little more money.