If you are going to choose a Holley system, I would suggest an original terminator kit if they are still available. They are a nice throttle body system with an HP computer. I don’t like the chinsy connectors of the terminatorX, or the fact that it is sensitive to environment like moisture/ temperature. It also is limited in the use of “wet” fuels because of the bosch only wideband. No on board data logging also means toting a laptop around if you want to get it zeroed in.
If you are making the switch to efi, it is cheaper to spend the ching on the heart of the system and be unlimited on upgrades down the road. An HP will get you a better harness, better sealed ecu, ability to run COP if you choose to, has on board data logging, and uses the exact same software as the flagship Dominator ecu. The HP is limited by only having a few extra configurable in/outputs. However, they do make an expansion module for it from what I hear.
Or just go full bore and get a Dominator system and log/ control anything you can imagine.