I'm switching from PC to iMac shortly and trying to determine what to buy or not. I'm going to get a 20" iMac. I'm used to a multibuttom mouse with a scroll wheel and think I want to stay with that. I want a wireless mouse and keyboard using iMac's bluetooth. What do I need to be shopping for? Are the specific Apple keyboard issues I need to be aware of as far as special keys or mapping? Can I just shop for bluetooth keyboard/mouse that is in the price and syle that I like?