We decided on a glass door system after browsing around and deciding that Sweet Pea would just pull down any screen that wasn't fully attached to the fireplace, and we have a smallish living room so we didn't want to totally baby-gate off the fireplace area. A door seemed the safest and most attractive way to go. However, doors can cost as much as $1400, which was not really in our budget for the month. We asked a sales-person for some ideas and she showed us a hidden upstairs area with returned and floor-model fireplaces and doors. The one she showed us that would fit our fireplace opening was not what I had in mind in terms of looks, but the price was right: reduced from $600 to $299. We went home to think about it, and a week later we were back to buy. While the door set we got is not exactly my style, I do think that it goes with the era of our home, and the style of the rest of the fireplace. It is a light gold/bronze color, and I prefer black or silver usually, but looking at it in our house I think it is really the best choice.
Average installed it himself with a borrowed hammer drill, a screwdriver, hammer, tape measure, 5/16 pin punch, and button-head concrete fasteners.
I was surprised that the fireplace store didn't send us home with any instructions at all, but am lucky to be married to a very handy man. He only broke one brick in the installation process, and it's hidden inside.