Thanks guys. Since then I have been looking at the "LaCie XtremKey USB 3.0" or the USB2U USBs in order to run Linux from (on a computer that doesn't connect to the internet of course):
http://www.lacie.com/UK/products/product.htm?id=10612http://www.usb2u.co.uk/articles/2011/06/bullet-proof-usb-flash-drives-–-ideal-for-students/
Of course, the LaCie is a great product as it's resistant to the heat/cold and drops from 10m while the other is, well, unproven.
Anyway, the LaCie has AES 256-bit encryption so it's approaching the others in terms of security features, but ticks a lot of "real world" boxes, if you see what I mean.
E.exchanger: I am not so keen on biometrics for the long term, sure on my iPhone, but in a SHTF situation, even in a post EMP-epoch (this USB's going in a Faraday Box by the way) I don't want the mechanics to fail on me and a telephone number to have to be rung or something.
Thanks.