Letter Re: Questions on the Pickup Truck as a Multi-Purpose Retreat Vehicle

Dear Jim and loyal SurvivalBlog readers:
I have been researching pickup trucks as my next logical purchase in preparation for the inevitable short or long-term SHTF/grid-down scenario.
I have decided that I will purchase an older (pre-1990/EMP-resistant), diesel, 4 x 4 pickup truck, probably a Ford, but maybe a Dodge or GMC/Chevy. The truck will need to be powerful enough to tow whatever (trailer, boat, camper) as well as be able to effectively plow snow (living here in snowy New England after all). My decision is based on reading the many postings on SurvivalBlog regarding the best G.O.O.D. vehicle to own (or at least, one of the best).
However, before investing several grand in 2006 dollars, I would greatly appreciate some guidance on the very best trucks to consider regarding the following questions (and my budget of around $3,000 to include plowing capability):
What years should I consider for each manufacturer to ensure that the truck is not vulnerable to an EMP?
1.) I want to be able to plow with this truck. Would I be better off to buy a truck that has never plowed and then outfit it with a plow? Or, should I buy a truck that is already equipped to plow?
2.) I seem to be leaning towards a Ford as there appears to be more Fords available than the others. Then there are the model variables to consider: 150, 250 and 350... Any personal opinions on makes and models are most welcomed.
3.) What is the best (most reliable) older diesel engine made? What kind of engine longevity could I expect (200K, 300K) considering the make and vehicle's overall condition?
4.) Please advise on any other purchase issues I should consider.

Thank you for your time and attention and may God bless you and your families and keep you safe, faithful, and hopeful. - David J. in New England