I gave up on giving/sharing ideas with folks here, too many close-minded "Daily Do-Littles" as I've coined the phrase. As you can see by no responses, not many folks here on this site are into doing anything to their cars other than pointing at them saying, I own a stock BMW woo woooo! God forbid if you personalize it or make it even better than how it came to you. That's 'spoiling greatness' or whatever.
Kindness of my heart leads to these links:
www.umnitza.com <-- Kings of BMW lighting
www.modbargins.com <-- massive mod parts selection for BMW's.
www.autowerks.com <-- Another good site for BMW mods and parts.
I would personally suggest you look into Prolumen bulbs. Why? Find em on those links and read up you'll see why.
You can always poke around on Ebay, do a search for 'BMW 1156 bulb' and 1157 bulb, these are your corners and brake light bulbs. Your side markers are 196 bulbs.
Good luck - don't let my feelings getcha down about this site, alot of good folks here - along with some rather uptight ones too.