I wasn't aware the Type 3s had a thicker rotor...?
The Euro/Aussie spec Beetle/Ghia rotors (and calipers) do a good job. I have driven US-spec cars (I own a couple) with drum brakes and they are woeful until upgraded
Even better with a rear disc... and yes you are correct about the Subi upgrade, it will tax the standard unvented brakes.
Maybe you need these!
https://www.facebook.com/media/set/?...1374496&type=3