The cheapest way might be to use your existing weber carb on a draw through setup. You can use the inlet manifold you already have. A turbo manifold will have to be made. Oil and water lines, carb to turbo addaptor, throttle cable, dump pipe to match up with existing exhaust. You will also have to make the pipe that goes from the compressor outlet to the standard inlet manifold.

Locking/welding the mechanical advance on the distributor is also required.

That would be about the simplest way to do it, but there is still a fair bit of fabricating to do.

The engine DOES have to be tuned properly if you want it to last more than 5 mins.

If you were to run unleaded, 10Psi would be safe/reliable(if tuned properly) as DD has said. If you were to run E85, you could go a fair bit higher than 10Psi.