For using the gasser as a pizza cooker, I'll report that I've been really pleased with the Gas Pro pizza inset from Kettle Pizza.
The set up is a stone or baking steel underneath the pie, and then a heavy, low, flat steel lid that cooks the top. The lid is 17x24, so it fits great on a new or old model Genesis grill.
It doesn't get you up all the way up to those 800F+ temps you need for true Neapolitan pies when using charcoal/wood as the heat source. Although you can put some pellets or a wood chunk at the back in the back of the insert lid to get smoke and a rolling flame going like you'd see in a true pizza oven.
Not cheap, but solidly made, good results and very convenient.
If you are only cooking a pie or two on Tuesday night, it can be a slow process to fire up the coals (15-20 mins), then heat up the stone and oven (15-20 mins), then cook pizza for 10 mins, then shut it all done and clean it up.
P.S. I previously had a Bakerstone oven insert for use on the gasser. It was OK, but was hard to get hot enough on my older Silver B.
Transform your gas grill into a pizza oven with the KettlePizza Gas Pro Pizza Oven Kit. The stainless steel enclosure and cordierite pizza stone sit on top of your grill grates to create a convection oven. This kit is intended for grills with at least 3 burners and a minimum cooking area of 24...
www.bbqguys.com
