I like the idea of a diesel engine,except the fact it's dearer than gas/petrol over here! Nearly $11 a gallon! Then again you usally get better mileage with the diesel.
VW do build some sweet diesel motors,or alternatively how about a BMW 6 cylinder or a Merc 6 cylinder from a Dodge Sprinter van. I don't think the Metric side of things should scare ya! It's only a different set of wrenches after all!
I do like the idea of the Audi V10 though,it develops more torque than a Dodge Viper!It would probably be a bit of a squeeze though!

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.