Mark, here's the thread for the IR burner setup:http://www.pizzamaking.com/forum/index.php/topic,9614.0.html
Pizza DOC is, without a doubt, NY style pizza:http://mypizzadoc.com/pizza.jpg
3-5 minute bake time. No more, no less. For this kind of pizza, a home oven, with the right stone, is usually the easier choice. The IR burner is a very effective way to achieve these bake times, but, because of the directional nature, you end up having to do more turns. In an electric oven with convection, you won't have to do any turns. The Bosch is electric, right?
If the Bosch can reliably do 550, then I'd invest in 1/2" steel plate- a square piece as large as the oven will fit. The oven shelf will have no issue supporting it, and, with the convection feature, you'll be able to pre-heat it quickly.
There's a chance you might be able to utilize steel plate in the grill as well, although I've never seen it done. If it were me, I'd go with steel for the oven and firebrick for the grill. Firebrick splits (1.125" thick) will take a little more propane to pre-heat, but their lower conductivity will handicap the bottom a bit and help the top catch up, should it need to. They will also be very durable.
This is for NY style, pizza DOC, thin, crispy, mostly brown pizza. If, on the other hand, you want as close to authentic as possible Neapolitan pizza (not really crispy at all), and are willing to push your grill to it's limits, then you'll want to compare your BTU output (on both the bottom burners and the IR burner) with Craig's, and, if they are close, then I'd invest both in a Fibrament grill stone and insulating blankets.