Don't be stressed too much, put an intercooler in there and add an EGT gauge. Don't shut the engine down until the exhaust manifold is cool enough (<200C).
The intercooler will give you a little bit more horsepower (not a huge amount, and it works better on cool days than hot ones) but it will catch ALL of the bits if the turbo lets go.
And Garretts can let go just as easily as Hitachi - what breaks is the bearings, and it's more to do with how much heat is soaking through them burning the oil up after the engine is stopped, than with the manufacture of the turbocharger.