Find out if Bekkers wants to sell you the LOW BEAM ONLY HID retrofit and if so, your best bet would be www.HIDS4Less.com, speak to Mike Chavez there and tell him that I (Sisco Matos form the 190 forum) sent you, your shipped price will be $499. These are beam-pattern corrected and are strictly plug & Play. I put them on my 190E with Euro Headlight assemblies (H4 bulb) and it took me less then 15 minutes after I opened the package. Make sure you ask for Philips bulbs, as I believe I was sold Osrams...all of their ballasts are philips, so that's not a problem.
P.S. Hella does not make their own ballasts, they are made by philips.