yes you can do all that, the driver manifold will bolt straight to the GTI head, then you can just get the webber tuned on a rolling road to suit.
As for the injector holes, you can just leave the old injectors in, and think about sorting a neater solution at a later date

Some suggest welding coins into the holes, and one guy got a local engineering place to fab up some plugs. But if you cant be arsed with that, just leave the injectors in

Edit: You can just swap the GTI cam into the Driver head for an easy life, but you wint get as large a gain as the GTI head has bigger valves in. The 1.8 lump will bolt straight onto the 1.6 head too, this will turn it into a 1.8 Driver
