get a laptop with 2 sata disks, install as hardware RAID 0
they are out there, but not cheap
your screwed if one disk goes south , but you'll get blistering speed compared to just one disk or even 2 seperate volumes on 2 disks
then load up on memory
and tweak your Windows so nothing runs that shouldn't run (disabling services, not installing crap you don't need
An as you install windows, one volume for OS, one for app, one for swap, maybe even one for data
sure it's a pain in the ass to keep crap organized, but your volume won't fragment as much and your windows speed won't degrade so quickly
fast cpu's are worth effall
if you're working with big files that chew up memory,
need to load from disk all the time and ultimately start running your windows swap file
http://www.dell.com/content/products/productdetails.aspx/xpsnb_m2010?c=us&cs=04&l=en&s=bsd