Help in selecting out of 4 notebooks/Tablet PC

Hi
I am a student & live outside US.I would be going to US to study this year.I am therefore intrested in buying a notebook & therefore searched cnet.com.I found 4 notebooks but am confused to buy which one(in US)???
Here are the laptops with their specs.

HP Pavillion zd800(I configured it for $2,760 on HP.com)
P-IV 3.4 Ghz,17'' wide screen,1 GB RAM,256 MB ATI Mobility x600,100 GB 5400 rpm HDD,DVD Dual layer writer,WinXP Media Center Edetion,Extra Battery,MS Works/Money,Norton Internet Security 2005,HP remote control,HP student bundle,HP Expansion base.

SONY VAIO A690 for $2,799
Pentium-M 1.86 GHz,1 GB RAM,100 GB HDD,ATI x600 128 MB,
17'' screen,Super Drive,Remote,Docking Station,WinXP home,TV,softwares etc.

Toshiba Qosimo G15-AV501 - $2,600
Pentium-M 1.8 GHz,512 MB RAM,100 GB HDD,WinXP Media Center,Super Drive,nVidia GeForce Go5700 128 MB,17'' wide screen,remote,TV,softwares.

Toshiba Tecra M4-S435 Tablet PC - $1,999
Pentium-M 1.7 Ghz,512 MB Ram,60 GB HDD,WinXP Tablet PC,
Dual layer DVD Drive,nVidia GeForce Go6200 TE 64 MB,14.1'' screen,softwares.

All the above laptops have bluetooth,Wi-Fi&at laesr 3 USB ports.