Sounds like the Panasonic connection has been covered. I think it's a CF-150b that is the same as the 1100, except it doesn't have Deskmate (and maybe not even DOS?) in ROM. I have one here that I've not messed with. I'd like to have one of the desktop models as noted, but not at current asking (or even selling) prices.
Tandy also made a 1000 AX that sold through Wal-Mart stores for a short time (same as the SX) -
http://www.megley.com/photos/tandy/1000ax
And then there's one I still haven't figured out the background story, it's a "PC-1000", which an SL clone -
http://www.megley.com/photos/tandy/pc1000
Wesley