Welcome to the board Vance
I enjoyed reading your intro and your plan for your truck. I can relate to the long build part too.
I have used the PPG DP Epoxy also. It is a good product but it is $$. But probably not much more than any other good epoxy. Another PPG primer that I've had good luck with is NCP271. I like it partly because it doesn't contain chrome, lead or isocyanites. You might check into PPG's Omni line epoxy primer too. There are other brands of good epoxy too, but not all that I'm familar with may be available to you. I've heard good reviews on products from
http://www.southernpolyurethanes.com also.
Let us know when you have questions or issues.