Have you thought about multi fit style wheels. They look allright with the extra holes and you can change them onto a another car if you ever got a new/newer car.
As for redrilling the holes, I imagine you would have to weld and redrill the holes as some wheels have gaps on the back and if you drilled into this you might affect the strength of the wheels.
As for the legality of this, After doing some research,
If you got an engineer to do this with a cad machine and a cnc drill so all the holes are the same I can't find anything that says it is illegal