[Northwest86]

A Supercharger is generally cheaper. But has less headroom generally. For a pretty reliable car with a hell of a punch that'd be excellent on the track. I would definitely recommend something like the Jackson Racing Supercharger. Don't get the Kraftworks kit unless your willing to deal with the issues they have had. Thats where the research comes into play. These are Positive Displacement or basically The compressor side of a turbo thats belt driven. They love to rev and any existing headers etc can be kept. The other options that seem to stand out are the Cosworth/Harrop SC that are a roots style that give tons of low torque but do tend to fall away up high. These can be excellent if its a street car that you want that overtaking kick without dropping to many gears.

A turbo can be a little more pricey sometimes but since power is often higher, things like clutches, gearboxes etc can add to price. All are good options. But honestly out of the American options. Only the Jackson racing so far has been 99% problem free to my knowledge and don't have heat issues which makes them great for the track. (Not including Cosworth/harrop since they are newer to the market) Everything gives you a good kick and it comes down to exactly which one you like and what is available.

Do you have a tuner (dyno) first. This should be the #1 investment because a good dyno guy can give more gains than anything else in terms of drivability. Get a good one whose worked with a ton of different kits. They will often have insight about many kits that you may not know of. Just make sure hes not a tuner that wants to sell you something.