James,
Assuming you have Weber IDF Carbs, Linkage and Manifolds now, you would need to buy an FI Pump, Pressure Regulator and an MSD 6a Box and some plumbing stuff (FI Hose, Hose Clamps, etc.). If you don't have the IDF's, add about $300 to the numbers below for Manifolds and Linkage.
I would recommend either the CB FI Pump @ $144.50 or a Vortech FI Pump from Summit Racing $155.
I would recommend either the CB Targa Pressure Regulator $87 (ugly but functional) or the Aeromotive AER1000-6 Billet Pressure Regulator available from Summit Racing for $135 (beautiful piece, great regulator).
The MSD 6a Box will cost you about $170, available again from Summit.
Both style fuel rails included in the deal, Billet with -6 AN fittings and Rubber Hose style that fit 5/16" EFI rubber hose.
I can't give you an accurate estimate for the plumbing as it will range from pretty cheap for EFI Rubber Hose and Hose Clamps, to pretty expensive for SS Braided Hose and AN fitting throughout. You probably would be hard pressed to do the Plumbing in Stainless Braided Hose and AN Hose Ends and Fittings for much less than about $400.
The map I have in the ECU should work pretty well for your engine.
You will have to install a fuel return line from front to back and have a return line bung put on your fuel tank to support the return line. Ideally the return bung should be at the same level as your feed port to minimize splashing as the excess fuel is returned to the tank from the regulator.