Wheel fitment , the facts?

[detailbarn]

Ok here is my situation I had my plan all work out how I wanted to build my bug but now it's falling apart, I'm close to giving up and selling the car.

Can anyone tell me the following:

What size offset will I need if I do 4 wheel 944 disc brake conversion?

Are CB's disc brakes any good and do they widen the track width if so how much? What offset would be needed if I was to run these?

Thanks for the help , I'm hoping to keep my project alive...