I reckon, ditch the bottom-end work (it will be the most dollars spent per HP out of this list). Ditch the 123ignition.
Use a better wasted spark ignition system that can read a MAP signal, knock sensor signal, a crank trigger, and a wideband. You will get data logging, knock sensor safety guardrails, and will be able to tune better. Good EMS these days can self-tune too.
Any will work with K-Jet, and you basically just ignore the fuel aspects other than I would use the EMS to switch the fuel pumps on and off as (a) without the factory coil your K-Jet relay won't have a running engine trigger signal, and (b) EMS can prime the fuel system automatically.
123/TUNE is nice but it is designed for people who basically just want to get rid of a points-type ignition but retain an original look. As far as programmable ignitions go, it is very limited.
Edit: if you want to reduce rotating mass, a lightened flywheel is a better starting point I think.