I got a 30 Gig Video model for a safety award from the company I work for (4 years with out a lost time accident). I really like it, I have about 70 gigs of MP3's on a portable hard drive and I just put a bunch of music on the pod and go. I work for 2-4 weeks at a time away from home and the pod is great. I have a FM transitter and charger for it (all in one made by Monster), that way I can use it in any truck I am driving and I plug it into the speakers I use on my laptop when in one place. I have not done much video yet but will shortly when I get the first two seasons of Deadwood converted for use.
I will say that I had Itunes, it took over my computer and made me angry.
Check out Anapod manager to transfer files to the pod, works much better than Itunes and no constant bagering to buy stuff.
I think no matter what IPOD you buy you will be happy, just be warned that the accesories are expensive. If I was doing something for just my truck I would go with sat radio instead.