Superchargers do lag. The degree depends on the size/design of the blower and how much boost you're maxing out at, just like a turbo. Turbos unfortunately have a bad rep in the import world b/c of people putting large and mismatched turbos on 2ltr and smaller engines and generally running higher boost levels which all produce lag. Think about a factory boost levels of supercharged vs turbocharged engines - under 10lbs in most cases for the sc and upwards of and over 20lbs on turbocharged applications.
As for the op's question, probably a supercharger. With a v8, it'll be easier to install/work on and produce great results.