5-point belts: where to buy and installation

[Chris Newbold <cnewbold@eznet.net>]

In preparation for 1997 drivers' schools and track time,
I'd like to install some 5-point belts in my car...

Does anyone know of a good source? Any particular brand?
(Most people I've ridden with use Simpson...)

And now the Audi content: Has anyone installed 5-point
belts in a 93+ 90 or 100 body-style car? In particular,
any tricks with hitching it to the power driver's seat?
What about the Procon-Ten system? Will that get in the
way of attaching the belts at the sides?

Thanks!
-Chris