I take it your M didn't come w/ HID?
Are you looking for optimal light performance over cosmetics?
Osram Silverstars +50: 55w, 1750 Lumens
Philips VisionPlus +50: 55w, 1750 Lumens
Osram UltraHigh Output: 65w, 2100 Lumens
They can be purchased through either Daniel Stern Lighting or PowerBulbs UK.
Stay away from high wattage bulbs unless you upgrade your harness. But even then high wattage bulbs have been known to brown your housing.
HIR technology for halogens are pretty dang bright.
http://cgi.ebay.com/ebaymotors...ZWDVW