If you feel guilty about it, go diesel. You'll have a little bit of a tough time finding exactly what you want unless you go used.
Reasons for diesel 1- lower HC emissions
2- much better fuel mileage reduces cost and dependence on foreign oil... or any oil for that matter
3- easy to convert to bio which drops your carbon consumption to almost zero
4- double (or sometimes triple) the torque
5- resale value. I'll say it again. RESALE VALUE.
6- despite uneducated opinions to the contrary, diesel has a decidedly lower cost of ownership over its life than gasoline. They typically carry more lube, and they require more frequent fuel filter changes, but having worked in fleet maintenance, start to finish a diesel will keep more money in your pocket by a long shot.
7- secondary benefits; diesel is cheaper to produce, transport, and store, meaning the distribution of it has lower carbon usage
8- diesel is a very safe fuel. If you happen to be in an accident where spillage is concerned, or refueling near an ignition source, gasoline is explosive. Diesel is very difficult to ignite without large energy inputs. In fact, ASTM biodiesel is considered a non-flammable liquid.
Your problem might be finding a suitable diesel that isn't a behemoth, but anything with the 7.3 powerstroke is a fair bet: E-vans, Excursions. Older Tahoes could be had with the 6.5L diesel, but that is hardly a wise investment given their potential for failure. Many of them are fine, but enough of them are lemony fresh that its too much of a gamble. In general, avoid the 6.0L powerstroke. They tend to have injector, turbo, and intercooled EGR issues, all of which are very expensive. Chevy vans can be had with the LMM duramax which is a slightly detuned version of the normal duramax. 250 hp instead of 300, but gobs of torque. You could tow 10,000 lbs behind it and not every have to use full acceleration to maintain speed. The only pitfall there is that I don't recommend upgrading the LMM's power much since the vans came with the 4L80E instead of the Allison 1000. They'll last forever in stock form, but its easy to double the torque with a chip and exhaust. Not nice for a 4L80E.
I also strongly suggest against an 08 and up diesel with the new DPFs and additional complications. They'll be fine once they get the kinks out of it, but right now its too new, and it was hurried along to meet EPA regs. Its kinda like buying a 1971 vehicle. They were the first of the hasty smog-compliant cars and they made weak power with a high potential for bugs. Dad has an 08 Duramax truck and it makes insane torque and 360 hp with a 6-speed allison, but whereas he could get 25 mpg in his 04 Dmax, he's only getting 16-18 with the new one.
It looks like you're thinking newer and posher though, am I right? Its my strong advice (even though I LOVE diesel) to wait out the diesel market. The new EPA-mandated changes are still new and need a few years to stabilize. I suggest you either be a soccer mom and get a big squishy SUV that guzzles gas, or find another dual-duty vehicle. Large station wagon perhaps?
I had to buy a truck for work. It pains me to commute 24 miles a day in an F150 with a 4.6L that gets 15 mpg on a good day, but once I'm at work I spend most of the day hauling engines, transmissions, car parts, trash, etc. I actually did the math once: If I left my F150 at work and bought a $2000 Tercel to commute, it would pay for itself in about a year.