I'm thinking single for simplicity but who knows. As far as the supercharger goes, I have put 5500 miles on it with no problems(other than premature balding ). The turbo will leave a lot more room for a water to air intercooler, its much easier to test the boost limits, no parasitic drag on the crank, etc...
If the motor ever blows I'm sure something much more user friendly would take its place.