Well the last one is Agathis as it says in the title so although some people like it it wouldn't be top choice IMO. The top colour is a yellow wash and the darker wood can be seen on the side. The other three I'd just go with which ever you like most (other than wondering why it was coming from Canada I like your number 1 best). There may be some difference just because of the light in which the photos were taken.

edit: also the Korean one is half the thickness of the Canadian one.

I ended up buying the one that is made, and sent from Canada.

Congrats. Please post a few photos if possible when it arrives.

The black stones felt a little bit lighter than the white ones (both glass) could just be me though.

Yes, the Black stones (slate, glass) are usually slightly bigger than the W ones (shell, glass).
(An exception may be the plastic weighted ING stones since they came from a factory mold
and so they could make the B stones exactly the same size as the W ones;
another exception may be the single convex Chinese clay stones?)

These are the stones I bought. It says they are a mixture of rock and glass.