silent, powerful, sleek pc setup, ask for comments

like to build one silent (no fan), powerful (for game), sleek yet not so expensive PC for my 5 year old, here is my config:

SILVERSTONE LC19B-R (120W fanless power supply)

+ Intel Core 2 Duo E8200 Wolfdale 2.66GHz 6MB L2 Cache LGA 775 65W
(under clock to 2.3g or any frequeny to remove the FAN)

+ Intel BLKDG35EC LGA 775 Intel G35 Micro ATX Intel Motherboard


Any comments like on apparent problems?

Will try to install Solaris 10+XP+Leopard... may sacrify the Leopard and Solaris X10.

thx...