I talked to my sister-in-law to see what she thought and she is going to ask him what he needs without him realizing she'll pass the list on to family. If he knows that we are putting together stuff for him he will go out and buy it himself so we don't spend money on him, just how he's always been...
Anyway I think we have a really good list together right now that should help him out. I know that the knifes they were issued in his first tour were dull and cheap, he broke a fair few, which is why I'd like to send him with a decent knife/sharpener. The HDD is a great idea, we'll pick up a 1GB external and pass it around so everybody can put their movies/tv shows on there.
Anyway, I am really thankful for all the suggestions and generous offers from you guys, having never served in the military I just really didn't know what we could send to help him out.