The only ones being sold now are TX and AX units, but they have pretty much been discontinued and replaced by i variants. AXi is Flextronics and Super Flower, HXi is CWT. Oddly enough, their CSm series is made by an OEM I don't know, Great Wall.
The CX400 is kind of an oddball and I always forget about that one. It was more of an introductory unit to see if people would bite at budget PSUs from them or not and it was made by Seasonic. I think they went with CWT to make the line a tad cheaper and provide a higher range that didn't compete much with their better TX units. My HX850 is CWT and it was fantastic when I used it.
Honestly I don't have much of a problem anymore with them not using Seasonic as an OEM. Instead I just decided to buy Seasonic. The 520w Fanless Platinum I have in my server looks ridiculously overmade and I couldn't be any happier but I wouldn't have any problems putting another HXi or AXi in my machine either.