This kind of thing can be answered by Google. Some may call me a douche for saying that, but in all honesty why are you going to wait for answer when...
*does a Google search*
I find the forum etiquette surrounding thread revival, repeated threads, and "use google" to be quite conflicting. I also find that I have a severe lack of sleep.
As far as I know already, pretty much all USB keyboards will work
If you're in the UK, then I recommend getting a 'Zippy' USB Keyboard as there is a backlight beneath the keys (so you can switch the light on and see what you're doing in the dark). I use one with my Wii all the time (In fact using it right now