I had a Sejin SWR-140(1) for a long time. Wireless, rubber dome, same layout as the GHSS. Basically the same size, too.
I liked it a lot, actually. For the last few years though, I could never seem to locate both the keyboard and the receiver at the same time.
Now that I look at the links that arc2 posted, I think the 140 might actually be the OEM version. I have a receiver for that one if that's what you're trying to find.