Many people here have done this 9006 to 9005 bulb conversion (myself included).
http://www.bmwe34.net/e34main/upgrade/more_light.htm
Since the BMW lights are ellipsoid like our SVX lights, I thought this article might be interesting to some people. I have an E36 and the stock headlights suffer from all of the shortcomings of our SVX lights. The BMW folks have a lot more resources than us poor SVX owners and have found some useful info that applies to us too.
http://www.bmwcca.org/members/AM/Tem...e_Be_E36_Light
Cliff Notes: The HIR 9011 bulb seems very good.
--Matt