turbo or supercharger
What car is it going on? some cars, like Subaru, are somewhat dependant on mounting. If this is for a non-turbo to turbo build. check the classifieds on some of the car boards, nasioc.com honda-tech.com or try turbochargers.com. Remember being fast costs money :-)
Don't go for cheap; go for CORRECT! Ultimately, you'll get what you pay for. If you cut corners on either the Blower or Turbo, you'll live to regret it.