Should pick up any Ant+ strap. I'm hoping my Explore (Santa's got it) will connect OK to my old HRM strap from my edge 705 - that's worked perfectly for 10 years (or more).
I've still got my old GSC10 sensors on two bikes also, so hopefully they will sync OK.
Decathlon's stuff is usually good. I've looked on Amazon, and there is loads of third party sensors available that work.