^^^^^This^^^^^
For A FWD car.
For a 4WD car I'd still only go for a hybrid K04/Loba L04XX/GTX2867RS as you still lose driveability as a Daily driver car.
If it is track specific, then the sky's the limit.
I'd also be looking at the CDL block for any of the above as the GTI blocks with big power would not be as strong or as reliable. 
GTX3071 with the smaller exhaust housing work really well with the TFSi. Big numbers and nice power delivery. You adapt to the way the power is delivered.
Strenghtened internals in a GTi block will be fine for up to 550bhp.
LO4XX - well you know what I and other tuners think of that one! 
You dont need 4WD to go fast. Its fairly easy to manage high power in a FWD car with a good setup and linear throttle.
I guess we will have to disagree on that one then Alex. I'd rather have the lower spool and instant hit of the smaller turbos for the road and not have to adapt my driving style to suit the turbo.
However for a purely track car I'd probably plump for something the size of a GTX30 something.
The reason I prefer the CDL is that you don't have to do internals and can still go to mid to high 400's with the faster spooling turbo's and be reliable. You simply cannot with a standard GTI engine.
I know what you think about the Loba L004XX turbo Alex, but then I guess you'll never be a convert. It does work well, make power, spool quickly and I've driven one on more than a few occasions to know.
