I have never used an Ooni oven, but based on my experience with other similar ovens, as well as others' experiences using both pellets and gas, I would suggest you look into the gas burner for that thing. Far more convenient, and consistent heat. As well as better flame/heat control to make on the fly temp adjustments depending on how your pie is cooking. Not too mention you can use gas in your garage during the winter (with proper ventilation).
Have fun, it will be frustrating at first, and addicting!