I did it...
I know it's not for everyone, but I was out shopping for a new/used vehicle, and anything that I was willing to buy that was reasonably fuel efficient and capable at the same time was $20K+, so I figured that for about the same $$ why not build up exactly what I want.
Sure, on paper it's an expensive 14 year old truck, but under the skin is new or low miles almost everything. The engine only have 30K miles on it, and diesels even last longer than the gasser toy engines.
Not to mention I feel good about running biodiesel made from waste vegetable oil (even considering converting it to run on pure veggie oil). You really need to want a mid-size truck diesel to do it.
For the record, my wife is firmly in agreement with those of you who say it is crazy. Talk about a tense couple of months when I brought it home...
By the way, DieselToyz does absolutely top notch work (they didn't do mine), and while they are a little on the high end of the spectrum, they are not out of the ballpark pricewise.