I just put the MSD 6A on my truck with a Blasster 2 coil and I love it. It made a big difference in how the truck starts, idles, and revs. The higher RPMs are so much stronger now, the thing just pulls.Buick-Petronix dizzy and an MSD 6A control unit\coil are what I'd think of first.
As for the Pertronix unit, I know they get a lot of good reviews, but the one I got was defective. I ended up going with a new OEM dist. and now my ignition is spot on.