Both work with the same concept. Turbo is more common & Im sure it would be easier to find help with upgrades, parts & etc...
One of the diferances is that a turbo is 100% gain because it is run off of the exhaust pressure. A super charger is not 100% gain because it runs off of the motor i.e. pulley type system. BUT, in the end you would gain because the supercharger would produce more power than it takes to turn it over.
I would personaly go turbo.