The Audi 4000 "cookie cutter" wheels are pretty light if those are the ones you are referring to. I think they are ET45, which is a bit high on the offset. But they should fit a B platform car (the Aud 4000 was a B platform after all).
BMW "bottle cap" wheels in 4x100 are a good choice too. They weigh about the same as the tarantulas, maybe a half pound more, and they are ET33 for the offset.
Miata wheels are the best choice. Some of those are under 12 pounds each. Some were actually BBS wheels made for Mazda for the Miata special edition models. But the Miata hub bore is smaller than VW, so some modification is required. You have to bore out the wheel centers to fit them on a VW.
The bigger issue with 14" wheels is the weight of the tires, and the added inertia from the larger wheel diameter. You can get 175/70R13 tires under 14 pounds. But 185/60R14 tires typically weigh 16 to 19 pounds each. Shop carefully for lighter tires for those wheels.
As for the brakes, the 10.1" fronts and 200mmx40mm rear drums work well together. That's a good upgrade, especially for cars that go very fast. But I don't know that they are necessary on a diesel. In my experience, the 9.4" vented fronts with 180mm rear drums are excellent for vehicles up to about 2400 pounds total weight at speeds up to 125mph or so. You just have to choose good pads to avoid fade. I've got 10.1" fronts and big rear drums for a turbo Rabbit project I've been working on, but that one will see track time and will exceed 135mph, maybe over 140mph. At those speeds, the 9.4" fronts aren't adequate no matter what pads you use.
On the diesel I try to stick with the lightest possible brakes because the car won't go over 100mph, so thermal loads aren't really an issue.