
Depending on how you plan to use your SUV, I might recommend also
browsing Trailer Boats and one or more of those Pickup, Shotgun,
and 4WD magazines.  The car rags mostly seem to consider recently
graded pea gravel to be offroading and ten sacks of redwood chips
to be a bedload.  Considering that most of these SUVs seem to be 
used mostly as robust station wagons, that's probably not a bad
approach, but if your applications are more demanding, pick your
information sources accordingly.

Of the three vehicles on your short list (Explorer, 4Runner, 
Pathfinder), I'd recommend the 4Runner as being closely based 
on a rather robust pickup and the Explorer for being comfortably 
carlike.  Don't know much about the Pathfinder.