My uncle used to own a body shop in the 60s, and here was his advice to me: It is OK to use a good rattle can primer, but use a high-quality primer sealant after your final sanding is done.
I'm sure you'll get 20 differing opinions on this, but I think the bottom line is what your vision for the truck is. If you want a #2 truck, rattle can work isn't going to do it and neither is a home shop paint job. I'm happy with my #3.5 (at best) truck, with all of the work done at home.
As far as brands go, I recommend you build a relationship with a local body shop from whom you can buy your paint and go with their favorite brand. That way, you can draw on their expertise (for free!). Again, a #2 truck is going to require correct paint colors, so that will likely limit your choice of paint vendors.
Have fun with your project!
P.S. Like Kevin, I have used Rustoleum, but I don't recommend it. It does gum up. It starts to splatter and cloggs completely with at least 30% of the can left. However, I have had good luck with the rattle can primer sold at the local auto parts stores, such as Duplicolor. It is quite a bit more expensive, but well worth it. Then, make sure your primer sealant is the same brand as your paint will be.
