Chokes control your pattern. Generally speaking, the more open the choke, the bigger the pattern. Additionally, steel shot usually likes a step or two more open choke than lead shot. Cycling is interdependent with the gun's action. MOST new autos will self adjust for different loads. Some may, as many did in the past, require you to change or rotate a gas piston or something.
For shooting quail, doves and small upland birds a improved, improved cylinder will do. Thurkey... you want a tight choke. Full or extra full for lead and modified for non-toxic shot. (non-lead shot gennerally requires a little less choke)
Google "what chokes to use for upland" or ducks, or whatever you plan to hunt and you will get your answers. Same goes for shot size.
Good luck.
I would stick with familiar makes... Browning, Benelli, Franchi, Beretta, Remington, Winchester and any of their autoloaders will shoot light through heavy loads just fine. I have read decent reviews on the Mossberg autos too. The more you get into it, the more you realize that the more "intimate" you are with your gun (ie: one that you really enjoy shooting and carrying), the better you will shoot and the more enjoyment you will get out of it. For this cause, I say spend a bit and get the one that tugs at your hearts strings, or you will buy it later after going through several.
Best of luck!