sgtblu, stick with the medium BCM Gunfighter, less chance of snagging it on something and can easily rack the slide with your pinky finger...
as for ammo, depends on what you're hunting, different bullets, different performances and limitations, since I reload, i try different bullets i want to use and different powders until i come up with a combination that is most accurate, same for factory ammo, find something that performs, shoot it and see how it does