1. Whatever you do, don't upgrade from the apple site. It's outrageously overpriced.
A place like Other World Computing is great:
http://eshop.macsales.com/MyOWC/Upgr...=Show+Upgrades
2. Shiny things look pretty.
3. IMO, stick with the mac mice. Wired/Wireless might mouse. the ease of setup is worth it alone. Can't speak for 3rd party mice...Most of them are 'designed' for PC, but work.
I know it's a little bit more, but for what it can do, the Airport Wireless Extreme is an awesome buy. Not to mention the configuration actually makes sense.
http://www.apple.com/airportextreme/