Gotta love sleepers. You can do both SC and turbo, infact, they used to sell an MR2 that was setup that way. It really comes down to the question of why rather than how. With a properly sized modern turbo, you have very little lag and can produce enough boost to make traction a serious issue on street tires. Most SC's can do the same thing without a turbo. You can combine the two, but your going to have a lot more things trying to work together, so you've got a lot better chance that something is going to fail.

A vortech SC and turbo? The Vortech unit is a centrifugal SC (looks like a turbo but instead of being turned by exhaust pressure, it's turned by the engine's rotation) which are usually critizied for their poor low RPM response (it works much like a turbo, making full boost at high rpms, but taking time to spin that high). It just seems strange to use that type of SC and a turbo. Usually you would use an Eaton/Roots style blower, which makes full boost almost off idle and gives you the low rpm power and helps feed the turbo which takes over on at high rpms. Seeya.