Pocket Hard Drive or Keypen to run Linux

[Dean Chester <dean.g.chester@googlemail.com>]

Hi
Im soon to be buying a new key pen/pocket hard drive that will have a
linux distro installed on a partition. What would be the best to go
for as key pens only have a certain life and the keypen will be used
daily. I know i shouldn't run it as a main OS off the keypen yet im
not allowed to install it on the hard drive of my school issued
laptop. I will be looking at either at getting 2 16gb keypens or one
big pocket hard drive. Will also the read and write speed be an issue
aswell?
Thanks in advance
Dean