If you want the baddest Diesel out there go with the Dodge, and buy an 06. The 2007 Diesels have Particulate Filters, PC-IV's (Which makes it harder for the tuners to modify) and have to run on ULSD, also Dodge and Ford have new Motors coming out next year (You don't want to be a Guinea Pig)-
Dodge/Cummins, 6.7 Inline Six based on the 5.9 (Est. 350 hp & 750 Lbs/Ft Torque) Stock, With an optional Aisin 6-speed
Auto w/2 Overdrives--->Badd-Azz
http://www.everytime.cummins.com/every/pdf/4103902.pdf
Ford/International, replacing the 6.0 with a 6.4 (Shares nothing with the 6.0, Thank God) Twin Sequential Turbos, Piezo Injectors
http://www.forddoctorsdts.com/bulletins/2007psd.php
Chevy/GMC, Duramax/Allison--Probably the best Engine/Tranny out there, put in the worst chassis on Earth

. They are just adding a Diesel Particulate Flter to meet the new EPA regs.
For everybody's info. The 6.0 liter Ford/International is the biggest joke in Diesel engine Community (Only in production 4 years, That should tell you something right there). Believe me when I tell you, I'm a Ford man,Bleed Blue, But when it was time to get rid of the 7.3 I went with a Dodge. I need a Motor that will last more than 100,000 miles. We have three -05 Powerjokes and each one has been back to Ford at least 10 times--WTF?? Keep in mind that these are work trucks and they are driven hard (Towing Bobcats and a lot of off-road use) But that's what SuperDutys are for, Right?? 10 Headbolts on a Diesel, WTF???
Here's my Truck- 06 MegaCab 4x4, 35"x22" Nitto Terra Grapplers, 2" Leveling Kit, Volant Intake, Silverline 4" Turbo Back Exhaust (No Cat) 5"Tip, Bully Dog Triple Dog D-Loader w/ Outlook Monitor, Silencer Ring MIA. Est. HP-407 TQ-874 (This is an Ext. using my Quarter mile time saved with my Outlook monitor, I have no Idea how it calculates HP/TQ, but this is what it gave me after running a 1/4 mile)