I've got a SUM 1200, with which I use an old Viglen-0325 keyboard. I think the old Amigakit-branded AmigaOne keyboard works, too.
The thing with these keyboards is that they don't have any extra multimedia keys, they are just basic 105-key cheapo PC keyboards.
When I first fitted the SUM, I had problems and had to ensure that it was very firmly pushed down onto the keyboard controller chip
