Nice Polo 9n3, of course it's nice as it's a GTi
Nice idea on the front badge being black.
Have you already got something in mind for rims ? For lowering I can really recommend you Eibach it drives superb and still the comfort is maintained.
As for the rims personally I would think of something like OZ Superleggera in 16 or 17" as they are real performance rims (low weight) and will look awesome (on a GTI) I think.
Here's a pic of the rims
Just my thoughts though.
Good luck further on with the little devil :p
Greets
Wouter