You can shoot foster type, typically called rifled slugs, through any choke except the extra full or special turkey full . However, manufacturers recommend using Improved cylinder. Probably more important than your choke though would be what you have for sights on your barrel. Its almost impossible to get any real accuracy when you only have the bead on the end of your barrel to sight with. Remington makes both smooth bore and rifled barrels with rifle sights as well as scope mounts for the 870. If you will be doing a lot of deer hunting you might want to look into getting one of these.
Hope this helps;
Tony212