I would stay away from any Summit or other (like an HEI made to fit a Mopar SB) system, most of those house brand items are made to work with chevys and fords (mopars and others brands are sometimes included as an afterthought).
The ignition doesn't know if it's hooked up to a Chevy, Ford or Mopar. Electrons are Electrons so i wouldn't worry about compatability, just assess on price, reliability and support.
IMHO, I would invest in a better distributor before worrying about purchasing an ignition box. The stock distributor is not phased well and the vacuum advance tends to hang up, plus it's not easy to tune the mechanical advance.
One of the all in one distributors from MSD, Accel, Mallory, etc. are better made and provide full adjustability plus they have a perfromance ecu built right in so you don't need a seperate igntion box.
