i have the original ext full choke that came with the gun is that a good choke or need a different one (which one) and what shells work good with out breaking the bank.
The only way you will really know is to shoot some shells and see. I am sure the choke will be good up to a certain distance. Maybe as far or farther than you want to shoot. You really have to shoot it to make that decision. I used Winchester Supreme High Velocity 3" 6 shot the last few years I used my 1300. They may not do good with your gun though.