The metal plugs on the carb could blow out under the increased pressure. Others have used epoxy on the plugs. Some have also set the entire carb inside an airtight box. Remember every pound of boost that comes out of the turbo is another pound of boost that the fuel pump must be able to overcome if it wants to push fuel into the carb. With a carb, you will not need a high pressure pump and regulator like you do in an EFI application, so a decent quality electric fuel pump and regulator should suffice.
Some manufacturers sell floats designed to withstand the increased pressure.
In most cases the same sized carburetor is used on a turbo installation. Many people use a side draft or downdraft Weber 40 or Dellorto. Your carburetor does not take into account boost pressure when it supplies fuel to the motor. Because of this you must take certain steps so that it supplies the correct amount of fuel when the turbo is at the maximum boost level. What most people seem to do is to jet the carb so that at max boost they have enough fuel.