the Asus EeePC uses a Linux based OS, i.e. no go for SU.
I would avoid a video card w/ shared memory (which are fine for and dedicated to office and internet usage) as well as ATI based solutions under Windows (besides maybe the FireGL stuff).
I would recommend a dedicated and nVidia GPU based video subsystem, preferred the Quadro FX CAD series, w/ 512 megs own RAM.
use Windows XP Pro SP2 instead of Vista, currently the OGL support of recent video drivers is more stable than the available Vista drives... will probably change w/ SP1 of Vista and future releases of video drivers.
check the Dell Precision series w/ Quadro FX GPUs integrated.. you also might want to select and buy as commercial user resp. company because of the opportunity to 'downgrade' from Vista to XP...
btw, because of missing multi threading of recent SU builds a faster dual core CPU is better than a slower quad core.. may obviously change in the future.
hth,
Norbert
(formerly known as 'ignorant' sketchup-forum.com admin scnr)