See this thread:
trying-to-match-oem-07-m35-hid-headlights-t573579.html
Since you have an HID equipped car, I would go with the Philips 85122 bulbs that are referenced in the thread from the TheRetrofitSource.com.
Otherwise, any of their other kits would work great. You can always get bulbs on EBay for $30...but personally, I would never do that.
Also, your bulb type is D2S. Just in case you do want to search the internet for replacement bulbs. Ballasts you can pretty much get any kind you want as long as they are 35w. I am running 50w on my car personally, but factory is 35w.