Sonos only sells one type of Outdoor speakers that you can view on their website. Whelther or not they will suit your taste for sound is strictly a personal decision. Maybe someone will recommend other speakers but again the sound characteristics will still be your personal decision. You may be better served consulting a professional in outdoor sound.

The general recommendation is to stick with the same brand of speakers, so Sonance in your case, but it’s really subjective to your personal taste.

BTW,  I have a similar setup, with multiple amps powering speakers in the back yard space.  I’ve been rather happy with it, particularly with volume control.  I do not have to make it so that one part of the yard is too loud just to be able to hear music at the other end.  You could possibly get all your speakers connected to a single amp with an impendence matching switch (maybe with volume control).  I didn’t go that route though as I was actually attaching multiple TVs, I had the extra amp already, and I wanted to control volume of the zones by app rather than a switch in a closet in the house.

This is helpful thank you! Did you follow the general recommendation of using the same brand for your different zones?

I am using JBL speakers everywhere outside, although I chose them moreso because I’ve been happy with how they perform, rather than trying to be brand consistent.