I've tried many variatons of studs and nuts over the years to varying degrees of success.
The issue is not parts rattling loose, its the studs stretching from the heat of the turbo. The only proper way around this is to buy inconel studs, which are expensive and only on the shelf in the USA (from what i found a year or so back).
On my latest build i just used normal M10 Stainless rod cut to size for the studs, Nordlock washers which do help although they arent really designed to be exposed to the heat of the turbo either and their mechanical proeprties worsen over tiem. I opted for M10 "K-nuts" (from merlin motorsport). They are a 12mm spanner size, which is ideal as one of the lower nuts on the Garrett flange has awful access, and the nut is flanged perfectly to the size of the washer. I've yet to use the car but fingers crossed.