The Gt series are water cooled >
For example the GT35R (GARRETT)is water cooled. but this is done by tapping into your engine coolant usually.
The water/alchohol injection is mainly for cooling charge air temps.
A garrett turbo and a good sized intercooler will be more than enough .
Unless you are worried about space, were as the AFTERCOOLER, would suit you best since they are usually smaller and can be fittted int otight spaces for that stealth look