I like and run the MSD 6 box. Its reliable. I believe the multi sparks help starting, idle and low RPM operation. It is also common enough that most towns have an auto parts store that stocks them for an emergency. There's no ballast. Depending on which version you pick, they have rev limiters and other features.

For the distributor, any distributor in decent shape with the right curve for your engine should be good. A re-worked stocker is fine or a higher end adjustable. The smaller cap styles have less voltage capability then the high end big cap style. Adjust plug gap accordingly. Plug gap and cylinder pressure largly determine the secondary voltage. More gap and more cylinder pressure make more voltage... up to the max capability of the ignition. Even though a MSD + Blaster coil may be able to produce 45 kv with a smaller gap, actual voltage will be lower.

With a stock style distributor, run stock type gaps - .0035" - and the cap/rotor should live a long happy life. With a higher capability distributor, you can open up plug gaps... although I'm not sure there is much benefit in the big gaps.