Javdoc, You can email me directly at:
harold@dino.com for more info. I also have photos I can send.
John, I didn't see the link to your bus.
I put together a disk brake conversion page a few years ago using Wilwood calipers and retaining the 112x5 bolt pattern.
http://there.dino.com/harold/bus.php
Since then I've seen a few different choices such as swapping 944 rear components. Do a search for "old speed vw", they make a conversion kit. There are a number of front brake conversions using 944 hubs and brakes. I'm in the midst of converting to 7 & 9 x 15 Fuchs, which requires flaring the fenders, still a few months out. I modified a 912 front hub to work with the v.w. disk brake spindles and a variety of rotors & calipers.
The 3.2/915 is the most economical in my opinion. I started with a 2.4E and didn't think it had enough torque or power. The next option would be a 3.6. I think think this is the best choice. A stock motor re-chipped and sport exhaust would get you into the 300-325 h.p. range. I figured $5K + over the 3.2 conversion.
As far as steering, there is a company in England that makes a rack & pinion conversion for the bus. They are also coming out with a variable power assisted steering kit.
http://creative-engineering.com/index.php?page=shop.browse&category_id=10&option=com_virtuemart&Itemid=2