Is it worth forking out the extra cash (normally around $50.00-$100.00) to buy a Kindle touch 3G + Wifi as opposed to a Kindle Touch Wifi only? Also is the Kindle good or should I go for a Kindle 5 or Kindle Paperwhite instead?

I'm looking at buying my boyfriend a Kindle Touch for Christmas. He works in AV, so often there is a long period of time when he just has to sit at a booth and be on call without needing to do anything and I thought it'd make a good pressie :)

I bought him the Kindle Touch WiFi from here and decided to use the extra $46.00 I saved (instead of buying the 3g model) on getting him a screen protector, case and booklight.

New question: Is there any good software programme to store and organise your important documents on the computer?