Ummm, you need to get the x86 32bit version as ammorais said..
Unetbootin must have a iso image to install to USB
you can get debian live cd or usb images, as you know
http://cdimage.debian.org/cdimage/re...ent-live/i386/
the i386 versions are what you need.
Debian Live can also run persistent from USB
which I assume is what you want?
that way, at each reboot/startup, your settings, apps added etc are retained
I made a wonderful Debian Live remaster featuring many many apps
and included info on persistent cd/usb/hd install
and also include 2 persistent "files"
1 is 250MB, other 500MB
check it out if you like
http://www.linuxquestions.org/questi...on-gas-766098/
I also made the above so you can make your own cut via remastersys and I made it so its easy to install
to USB from iso without using dd.