I love my Magic Mouse on my new iMac, but I understand that it doesn't work so well on the MacPro. I have a Logitec wireless mouse at work on my G-5 tower, and it's fine. The scroll wheel occasionally decides not to scroll, but that's all. The Logitec mouse isn't Bluetooth, it uses some sort of USB dongle.
As for the tablet, I use the big Wacom Intuos 3 at work, and bought a cheap Wacom Bamboo for home use. DO NOT DO THIS! The nib on the Bamboo pen moves around, which completely destroys any sense of control. The tablet itself is small, and there is no hand rest area, making it very uncomfortable to use. I need to suck it up and spend the money on an Intuos tablet for home.