Check out the HP nx6000 series. You can get them with a Pentium M or Turion. I know the nx6125 Turion starts @ $999 and includes a 3 year warranty, biometric security, and bluetooth standard; 15" XGA/SXGA+.
Maybe a Dell Inspiron 6000 15.4", but only a nicely loaded one using a fat coupon to make it $1300 or less. Won't be very portable though.
And just an FYI, chances are that you won't actually use your CAD software on YOUR machine. Most universities have labs & clusters setup to use their uber-expensive software, unless you want to buy your own. And most of the student-purchaseable CAD software isn't very demanding; just get lots of RAM since its dirt cheap now.