Loaded question. How do you plan to use the truck? Street? Off-Road?
Makes a huge difference on answering the maintenance question. Generally H1's are expensive on maintenance compared to an H2, etc. I've found the big challenge is in the suspension components, i.e. pitman, idlers, etc. but then again I tend to be a bit rough on the truck. I've spent the better part of the last 6 months away from the offroad scene and sure enough my maintenance costs have gone way down
If your looking specifically at a 2001 or 2002 there is really not all that much of a difference. 2003+ you start seeing lockers and interior upgrades. 2001+ you have TT4 which some will debate is not as good as 1997.5 trucks w.o. it for offroading.
Just a couple of points. More with more details