In all honesty, I don't think I would really consider any sort of forced induction on an SVT without an intercooler. Water/alky injection works, but is no replacement for an IC, especially on a street car.
Properly sizing the turbo(s) for an application is absolutely critical (though I find it humorous that OEM's rarely get it right) to avoid running the turbo's in a highly inefficient region of the compressor map, and to also avoid too much restriction on the exhaust size, while still maintaining a deirable boost threshold. Correct choice of turbomachinery is just as important with one turbo as it is with 2 or more.
