As you have discovered, the monitor is easy. The
keyboard and mouse
are the hard parts. They are an SGI design, so you need to get an
SGI keyboard. You can occassionally find them on eBay or some
of the resellers have them as well. You are probably looking at
$30 at the minimum.
Hmmm, I know I have a SGI keyboard, but didn't they make a couple flavors
that are different. I really need to get my stuff in a list.