I dont have any experience with an "electronic carb", but I have some experience with MPFI. People I've spoken with and worked with that have used kits like Snipers and FITech's have sold them and gone MPFI in the end and ended up with way better drivability and economy. Watching this Haltech video on transient fueling (
https://www.youtube.com/watch?v=DMT9kVO7fUU), it will help you understand why MPFI helps with throttle response and drivability. Most ECU's these days will take a locked distributor input signal, but you'll be left with a batch fire injection system. To get the best benefit of an EFI system, sequential is the way to go. Coil per cylinder is even better because you don't have to worry about things like distributor phasing or needing to use an MSD spark box to get enough spark from a single coil at higher RPM's where inductive coil's don't have enough dwell time. My 2c.