I bought mine from Mouser Electronics, but it is available from other sources as well.
You need to have a USB PS/2 keyboard, not just a USB one. If it comes with a PS/2 adapter do-hickey, you have the right sort.
I had to get an actual 32G miniSD card and load it with the AgonLight2 specific template to make it work right. Nothing from other sources seems to work right.