Any USB keyboard or mouse that complies with the USB 1.1 "Boot
Mode" keyboard and pointer rules should work with Sun Ray. Your
biggest problem is likely to be that some PC-market USB keyboards
don't identify themselves as having a particular localised key
layout. If you have one of those then Solaris won't be able to
automatically find the correct keymap for it, so you'll have to
experiment with 'xmodmap' or play with your system's default
keymap until you find one that matches the keyboard.
ottomeister (no longer @my-deja, now @mail.com)
Disclaimer: These are my opinions. I do not speak for my employer.