That's a lovely machine there! I've got the Performa 475 (same thing-just a different name) and it's also in near-mint condition.

As for keyboards, I love the keyboard which it came with (it was the same one as yours). I find it's nice in that you can rest your hands on the keys and they won't press, but when you get going at like 65 wpm (which is usual for me) then they simply collapse under your fingers when pressed which allows for high speed.

As for power supplies, I didn't know there was an issue with them. I guess that affects the Performa as well?