someone was selling a Supra with the Blitz TT's not to long ago, sont know if it still for sale. I havent heard any numbers or characteristics of the turbo yet, they are still fairly new. Also, the KKK turbos have been tried and trued on Turbo Porshes for more then a decade now.
The Blitz turbos are smaller than say the 2835s and they are also Kx3 turbos but they are pretty good. All the bs about custom work is exactly that BS. Also from what I was told it has decent power the draw back is the size if it matters. The kit seems more for those who want to show and not go.
mind you Kx3 is stock in a porsche.. make of that what you will.