To Ballast or not to Ballast?

An internally resisted coil doesn't need a ballast.
A stock style Mopar canister coil does, or it will get hot.

For a run stand I would probably opt for a C or E core coil like the newer trucks have.
It doesn't need a ballast, is small, puts out a great spark, is easy to wire up and isn't oil filled or cooled.