Hate to damper the enthusiam for an indoor oven, but....
Last pizza party we had here, there was a couple that we had to give instructions to on how to pull out the dough, cook the pizzas, etc. Clearly novices when it came to a WFO...
Now we'ver been over to their house before, and there is huge masonry unit sitting between the living room and the kitchen. I remember that it has a fireplace opening in the living room, but other friends maintain that Terry has a pizza oven opening on the other side into the kithen, so questioned them about it.
Turns out it does have an oven like everyone said. Terry said it (the entire masonry unit) was built at the cost of several thousand dollars. They had a few people over a few time swhen they first built it eight years ago, but that the oven just heated up the house too much and they haven't USED IT SINCE!...
From what I remember of it,and from Terry said, this oven was built to very high standards with all the proper chimneys.
Guess the moral is, something inside the house operating around 1000 degrees is just going to throw out a lot of heat no matter how well its designed or built. If you go the indoor route, really think hard about super good insulating doors and etc.