Most Devices designed for outdoor use use zigbee, not zwave, because zigbee travels somewhat better through rain, snow, and high humidity because of the type of signal modulation it uses. (DSSS vs FSK). Or they use other frequencies altogether. So there just aren’t many outdoor security systems based on Z wave.
Add to that that these days most outdoor security cameras have their own built-in motion sensors which will work much better then separate inexpensive PIR sensors for a number of technical reasons, and I think most people would just approach this problem differently. You select the cameras that you want and choose a system with built in motion sensors and sirens. And maybe you add additional inexpensive motion activated lights as well.
But I don’t see many people using standalone motion sensors outdoors these days. They just get too many false alarms.
One of the most popular DIY camera systems is the Arlo and there is an option with a siren.
https://www.amazon.com/Arlo-Pro-Security-System-Siren/dp/B01LR8PG52
But there are a number of other brands as well. So I would start from the cameras and I think you can find a combination of features that you want that way.
If you really want to look into outdoor motion sensors, there is an FAQ in the forums with a lot of discussion about many different options.
But if you want cameras anyway, I’d just start by looking at cameras. 