public Dictionary<string, MonoBehaviour> registry;
    public MonoBehaviour testComponent;

    void Start(){
        registry = new Dictionary<string, MonoBehaviour> ();
        registry.Add ("TestComponent", testComponent);
    }

    public MonoBehaviour GetScript(string name)
    {
        return registry[name];
    }

foreach (string comp in blockInfo.components) {

    //For each of the components that need to be added

        gameObject.AddComponent(ScriptMaster.compReg.GetScript(comp));

        //I know this is incorrect, but the idea is there
}

//you should be able to get the correct name by typeof(T).FullName
// or instance.GetType().FullName
foreach (string compTypeName in blockInfo.components)
  gameObject.AddComponent(Activator.CreateInstance(null, compTypeName ).Unwrap());