Hi Kyle; Welcome to Permies!
Well I went and checked out kettle pizza. Pretty cool item. Like weber, they think highly of themselves, cost being over $150.
I think if you want one of these, just buy one and place it on a weber. Done deal no building.
A rocket stove can and has been used as a pizza oven or cook stove. Folks like using Woks with them.
In my opinion, if you want a wood fired pizza oven then build one with brick or cob. Here is a link to a brick arched oven you build in a day.
makezine.com/projects/quickly-construct-wood-fired-pizza-oven/
Permies sells plans for an awesome double chamber
cob oven , although its not a rocket oven.
Have you built any rocket stoves / mass
heaters ? If not, I suggest getting some bricks and experimenting in your
yard.
Reading the posts here at permies will teach you a lot and getting a copy of the
Rocket Mass Heater Builders Guide is invaluable when learning about the proper way to construct a
RMH.
Welcome to the wonderful world of rocket science!