there is no reason nowadays to buy a new gas truck unless its an import.
the diesel will hold its value way better, get better mileage ( not as much anymore but still), tow better, have way more grunt/power.
benefits of gas... its cheaper initially. sounds good with the right exhaust.
New Chevy's and GMC's that cut 4 cylinders off at cruise sound like chit, don't ever ever ever put exhaust on them, you will regret it as my buddy does for the rest of the time you own it.
As for diesels, if you're going duramax, lurk over on DieselPlace it is an awesome forum with every thing you need to know about them.
a good used 2006-2007 classic will be your best bet (LBZ with 6 speed ally and no emissions crap), next best bet is a 2004.5-2005 (like me but you need to change out the intake + turbo inlet because the LLY's is really restrictive) or a LB7
WITH the new injectors that fixed their problems.
Anything past 2010.5 stay away from it, and that goes for Ford, Dodge, or Chevy. The government is killing these trucks with their emissions requirements and they all have the new Urea exhaust injection (urea is a chemical injected into exhaust after the engine that burns off excess pollutants). This crap is about 5 to 6 dollars a gallon around here, and if you run out and forget to fill it (atleast on chevys) truck goes into limp mode, every time you start it after it has limped itself it will restrict you another 5mph (limp keeps you under 55? initially) until you're crawling along at 5 mph back to the dealer.
I can't say enough good things about the cummins 6BT, that motor is ridiculously strong, I would own one except I hate Dodge transmissions with a passion. That last part is personal, don't use it to make a decision.
As for Ford, straight from my Ford loving friend's mouths, they've been going down hill since they ditched the 7.3 (this is there opinion, I have none of my own on this issue).
and since we're pic-whoring, here's my LLY baby with the few small mods I've done to make her scoot a little farther...
Chipped, leveled w/ cognito A-arms, new shoes, and new bumper thanks to a suicidal doe
