I asked someone else this recently and they said that the best ones are the ones made by Elbox, but I can't confirm this as I am still yet to get one. [Reply]
Personally the adapter that was supplied with my power tower which allows me to plug in a A3000 keyboard is the best but they're difficult to get hold of. But the PC-Key 1200 looks very similar so i'd imagine it's pretty good. [Reply]