First off I'm aware of the amount of work required to switch to coil packs from the standard distributer set up ie: aftermarket Ecu, tuning, potentially installing a magnetic based cam position sensor etc.

Second the build plan:
B18c1
Fgk jasma header
Aftermarket high flow cat
Full stainless steel exhaust
Skunk2 stage 1 cams
Skunk2 cam gears
Undecided aftermarket Ecu (depends whether I go with coil packs or not for coil outputs on Ecu)
Port and polish head
General maintenance ie: piston rings, lifters, lift springs etc
Obx individual throttle bodies

The question, given my build plan I am going to be upgrading the ignition system with either individual coil packs or an aftermarket upgrade on the distributer system ie: msd distributer kit. Which would be the best route to go and what gains would I be able to expect from either coils or an upgraded distributer?

 

I don't know the specific benefits on a mild-ish naturally aspirated build. I would imagine it wouldn't make as MUCH of a difference as on a forced induction motor, but spark quality would definitely improve. Maybe good for a few HP?

That being said, I have a full OBD1 B-Series MSD Billet distributor with Blaster Coil setup for sale if you haven't already bought one. Asking $400.

 

If you're going to stay with an oem-ecu based ecu, it's a flip of a coin. You'll run better with a conversion and possibly pick up a couple points of power and efficiency, but the cost to convert is high... high enough that you end up spending almost as much money as you would have spent on a proper standalone setup. If you're already running an Infinity/Haltech/etc, you're selling yourself short by staying with the distributor IMO. If I was starting from scratch with the latter, it would be a no-brainer to go with coils right out of the gates. If you wanted to step into it, most aftermarket ecus can be confirgured to run off of the original VR sensors on the distributor (they are universal ecus, after all). This leaves you the option to decide later if you want to move to an AEM epm or to move the cam/crank sensors to the front of the engine (which is the best but most complicated option).