Before you select your EFI system, is your car an automatic trans car? If so does it use a kick down rod that connects to the carburetor like the FMx, C4, or C6 trans? If you have any of these conditions, the Sniper EFI is not set up for Ford kick down linkage. The only EFI I have seen that is set up to work with Ford kick down linkage are Holley's Terminator systems.
If I were to switch to EFI I would also install a single plane intake manifold like the Edelbrock Torker II or a used Holley Street Dominator.