I doubt Andreas will be available in the short term, the last I heard he has unplugged himself for a couple of weeks holiday and he seems to be very busy.
I also don't know if this forum has a large pool of security experts with the particular skillset you need, it might be an idea to try grabbing attention over at bitcointalk or other alt-coin-gatherings (forums, irc, twitter etc.) The larger alt-coins might have some experience with attacks like these, so I'd recommend trying some litecoin-devs or Feathercoin and such. One of the Feathercoin team-members is very public active online and seems to be open to other projects in the same space, so you could try asking him. I can only remember his first name is Chris, but searching for chris + feathercoin on google, twitter and youtube will help you find him.