Sorry no photo pron but wanted to update this thread with my experiences.
I picked up 2 pizza stones from Big Lots, $10.00 each, 16" stones.
I first tried a cheapo frozen pizza in my Flat top/1 cooking level UDS. Opened up 3" of air-intake and the UDS ran around 350 degrees constant. The top of the pizza/cheese didn't want to brown up, the crust did, we ate it anyways, there was some smokey goodness to it and we couldn't resist. Pizza package said to cook at 375 for 14 minutes, ours went about 25 minutes at 350.
Round 2: Used a Weber topped, 2 cooking level UDS. Put a 16" pizza stone on each cooking grate. Again, 3" intake 4" exhaust, about 350 degrees constant. We were hungry and ended up with a pizza on each level. Some logic lead us to believe the lower cooking grate/pizza stone would have browned/crisp bottom and the Weber lid would reflect heat making the top cooking level/pizza stone brown on top. Must have been beer logic cause the results were not what we expected.
The stones diffuse the heat nice. Surprisingly to us, the lower cooking level, trapped between two pizza stones, produced the ideal "baking" results. Somehow those two stones created a nice reflective heat system. The pizza placed between the two stones crisped up on the bottom and the cheese and toppings browned up nice too.
In both runs I used RO Lump, no wood for smoke. The cooking process added some smoke flavor, the best results came from cooking the frozen pizzas between two cooking levels with stones on each.
I need to modify my UDS lids a touch for more exhaust to attempt 4" open air-intake, maybe 6" exhaust to insure updrafts. I'm hoping to ramp the UDS up to a 375 range.
At 375 with two stones I'm thinking I could just about bake anything you'd like to have some smoke added to. I'm imagining sides of pizza, corn bread, and the like.
Rich (eatrbbq.com) Weber, Chargriller, assorted UDS