to be honest, if I had the space in the corner of my garden I wouldn’t build a permanent pizza oven, but a decent, weatherproof, covered ‘kitchen area.
something out of bricks with a granite top.
I’d then invest in an ooni gas oven (waddya know.. I’ve got one! ) and a decent Weber BBQ of a size that fit my needs (ooh… one of them too) and then simply use the DECENT outdoor work space with the ooni/weber/both on it.
you’ll get much more use from it, and will be much more versatile.
not sure if the cost would be equal, but I personally think it’d be better..
DrP