For what, use in a camera? If so which camera, as older cameras can't take newer cards. Very old cameras may not be able to use SDHC, and so not SDXC. Some more recent cameras may be able take SD and SDHC, but not SDXC. An internet search for 'can my camera take this type of card' usually gives up the answer. Generally it is always a good idea to go with recognisable brands, if they still have fast 2Gb cards out there.old tech now but what's the best to use?
You're right of course, I was too eager to reply that I didn't remember why the new formats came out, to get past the 2Gb original SD design barrier.If the OP is only after a 2GB card then whether it's SDHC or SDXC is a red herring as it can't be either of them.
I think there are still many 2Gb cards out there, but not many by the big brands,who have shifted their stock years ago replaced by higher capacities.The best card of the time was probably the Sandisk Exreme III but cards that small are now almost unavailable new.
If the OP is only after a 2GB card then whether it's SDHC or SDXC is a red herring as it can't be either of them.