Summitracing.com is about the only good vendor who KNOWS EFI systems. You should talk with them.
They sold me a unit, made by a company who ONLY makes EFI systems. FAST (Fuel, Air, Spark Technology). I looked at Holly, Edelbrock, MSD, and many more. Then, I bought a FAST Fuel Injection EZ-EFI Self-Tuning Fuel Injection System.
The price depends on what components you need. If you have a programmer or an electric fuel pump the price drops dramatically.
When I install it, I will post pictures. - Dave