DEFINITELY go with the diesel.
one of the guys at work at pax has the V10, and he wishes now that he spent the extra cash on the diesel. Where you see the difference is in towing or with the bed loaded. The V10 mpg takes a nose dive where the diesel doesn't show much difference.
Also, in resale. generally speaking you'll get $5000-$7000 more on re-sale or trade in than with ANY other gas engine. $5,000-$7,000 is the difference spent when you buy one though too. Save some money and buy used! (if you haven't already considered it). I got an awesome deal on mine. Less than 2 years old, 20,000 miles, leather and loaded, for $12,000 less than had I bought it new.
I have the diesel, and I have no regrets. I love it.