I'm looking for door & window contact sensors and motion sensors to replace an old Simon 3 ADT security system. I've read a lot of posts and such and I'm still having a hard time picking out sensors that will work with an existing Smarthings v2 Hub (currently used for lights) and eventually Home Assistant once life calms down a bit more and I have time to go through all the setup. As I understand it, matter/thread support was added in the v3 hub so I don't have this on my ST v2.

I'd like to avoid anything from Amazon and locally functioning sensors are preferred.

Can anyone advise on how to pick good devices? There seems to be tons of info out there, but I'm having trouble sifting through it for the info I need. This is a surprise for a family member who has been considering replacing an older system. I'd like to get it in place before they have the chance to buy a crappy, locked down, spyware riddled system from a company like Amazon so that I can be sure everything will transition smoothly to Home Assistant later.