Opinions needed on Tow truck - Diesel or Gas?

[Pantera]

It is a old Ford show car hauler and the front car is ramped up into the nose of the gooseneck area. It is a 7 1/2 ft roof height too. I have a feeling that I will wind up springing for a whole new rig both trailer and truck. There is always someone that has a nice used one for sale. I can always sell mine. Heck it is a '78 model. Chapparall has been out of business for a few years now I beleive. I don't know why but I always loved the look of their trailers. But they are sure heavy!