Most fireplace glass doors are made of tempered glass with either ceramic or anodized aluminum frames. Glass is placed on the door so that the fire can still be appreciated even with the door closed. Most of these fireplace doors can be bought stock - meaning that most of the door that are for sale can be purchased off the rack and installed with minimal changes.
These days just as fifty years ago a minimum list of fireplace accessories includes only a few necessary items. Nothing new was invented in the last century. Today you will need a set consisting of a poker, a shovel for coal, also brooms and tongs. Add to this list a screen that helps to adjust the flame, a grate and log holders, and that's probably going to be all you have purchase for the fireplace.