MSD Distributor for 350?

[Sagesurfing]

I have a Blueprint 350 5.7 in my 1972 K5.
It's always ran a bit rough. For years I hunted down a vacuum leak. Then I did an engine swap and it still had the same kind rougher around the edges issues.
The only thing I haven't changed yet is the distributor.
What I have in it is a GM HEI. If I swap it out, I'm leaning towards MSD.

Any recommendations for MSD Distributors? I don't want the kind where I have to also install an external ignition controller. I'm not too worried about cost, would like to keep it under $400, but also want to just have it run real nice (and maybe better fuel efficiency?)

So let me know which MSD's you've tried and what worked well!