Best LS for 1/2ton "work" truck?

[yossarian19]

So, I realize this is inviting a lot of controversy, but..
For a 1/2 ton work truck (not a hot rod, not a drag racer, not a full ton horse-trailer-hauling monster) which LS is the best bet?
The 4.8 makes almost twice the power of the stock I-6, so it should be fine power wise.
The 5.3s make more power but I'm not sure if they'll get better or worse fuel economy in a 3400 lb truck.
The 6.0 seems like it would be overkill, but maybe not?

When done, the truck will be used to help college kids move on the weekend (side work = spending cash), haul loads of fire wood, or maybe once in a while to tow but probably never more than 5K lbs (and even that is a stretch, as I don't currently own anything I'd need to tow). When the truck is done, I'll start on an in-bed camper project - 1000 lbs or so.

So for the duty I have in mind, and recognizing that MPG is meaningful here, which LS series engine do I want?