RR11- I was in a similiar situation. I wanted an F250 Crew cab but didn't really think I needed the diesel- We only tow about 10 times a year and the rest of the time I drive 5 miles a day to work. I ended up with the V10 with the 4.30 rear.
Pulls great. I get about 11-12 mpg without towing and around 10 towing. I actually get better mileage towing with the V10 then I did towing the same trailer with my V8 Durango. Good Luck.
2001 F250SD 4x4 Crew- V10/Lariat 4.30 Rear- New Ride-Rites
*NEW* 2005 Durango by KZ 295BH 30' bunkhouse
I get 10-11 mpg around town, 13 or so mixed freeway/town driving and about 9.5 towing the 5,100 pound trailer in my signature. The engine is quieter and much more responsive than the 7.3L powerstroke, but I think the diesel is a better choice if you tow more than 8-9k.