I'm sure every system has its way of managing the ignition. I'm using a FAST XFI and can speak to how it works the ignition system. I chose this system because I already had experience with the system, because they are an older system they can be found cheaply(paid about $500 for mine used), and there is a strong knowledge base out there for support. So based on the FAST EFI system a stock or aftermarket distributer and MSD box will work in batch fire or unsynchronized sequential mode. Depending on how advanced you want to set up the system, a dual sync distributer(both cam and crank signals) or a modified stock or aftermarket distributer with a crank trigger will give the proper signals to work in a true sequential mode. The distributer can be lock down and the computer can manage the distributer advance.
Just about any injector, throttle body, and sensors can be used with the system. If you have any wiring skills its not to hard to make your own harness. I had bought a custom unterminated long harness and mounted the FAST XFI above the glove box. I added a flex fuel sensor and used another stock hard fuel line run next to the primary line as a return. The fuel tank is a Tanks inc EFI compatible with an in-tank EFI specific Hellcat pump and proper in-tank baffling. The EFI can even PWM control the fuel pump and I also use it to control the gear vendors OD in place of the Gear vendors computer. In my case I had bought an Edelbrock intake that had the EFI injector holes already machined and a matching set of rails.