Oddly enough, I have the PDF from the Berliner Weisse seminar from NHC open on my computer. If you are an AHA member, they are all posted along with the audio. Based on the extensive testing, it was found that pitching the lacto first, followed by the sacc, will give the most sourness. In the given recipe (which produced a very sour, and most authentic sour profile) the lacto was pitched at roughly 93F, and then 7 days later the sacc was pitched at 79F and cooled down into the 50s over a couple weeks. Note, that in order to classify this as beer, a single medium sized hop pellet was added to the boil. Other than that, no more hops!
Good luck. I'm excited to try my hand at a Berliner.