Yes - either the LRS or the standard version (NG I think).
There are a few options - EM358x and EM357. Both are still available, but if you buy the MeshConnect USB stick, then they do not come with any firmware and they are not easy to program. I can program them if needed.
Yes, there is also a RPi daughter board from EleLabs -:
This comes programmed.
Yes - unfortunately it’s not available without the developers kit. I can make it available though, and once programmed once, the binding is able to perform firmware updates.