electronic ignition conversion recommendation

Presumably you currently have a points distributor (pre-1972?). Simplest for you is the Chinese "ready-to-run" HEI distributor ($45 on ebay). Mostly good reviews here. The 8-pin HEI module (TrailBeast kit) will let some after-market engine controllers command spark timing. You can get the same parts cheap off any 85-95 GM truck in the junkyard. For any HEI control, bypass your ballast and run a better e-core coil. If you buy Pertronix, get their II or III. The original still uses a ballast. Much info here. Search and read.