Lots of variables here. It depends on your preference; go to a sporting goods store (not Wally's) and try shouldering and pointing a few. The two most common types used around here are the pump and semi-automatic. Usually in the 12 ga. version with 3" mag. shells. Most shotguns now come with screw in choke tubes, and from the factory they are usually modified chokes.

For turkey hunting you want either a full or extra full choke. The tubes usually require a wrench to remove and install new tubes, unless they are extended past the barrel. You can usually buy the chokes wherever you purchase the gun. Most any of the major gun maufacturers make god shotguns: Remington, Winchester, Browning, Mossberg to name a few.