I preordered one from amazon.de and it was dispatched around the correct date, though it has yet to arrive (I'm in Greece and chose the cheapest slowest shipping, sucks), it should be another week.I'm still waiting for amazon to stock the Saturn USB controllers.
They appear in stock there still.
Find them on other Euro-Amazons here with very specific search terms like this, it's what I do when importing stuff:
https://www.hagglezon.com/en/s/retro-bit official sega saturn usb
Or remove words like USB and Saturn if you want to include the rest of their range (wireless pads, non Saturn, pads for the original consoles with the retro ports etc).
I dunno about d-pad differences between Genesis and Saturn, I only ever had a Saturn but they look similar enough on these products. As with the videos above all of these things and even the 8bitdo M30 appear to be pretty good and fit for purpose according to hands-on reports. We'll see...