A good way to find low awards to Europe is to use airfrance.us. Just sign up for a free FlyingBlue account and then search. You don't need any miles in their program to do so. You'll be looking for "classic" (not "flex") awards in business class, which will require 100K DL miles per person. Ignore the taxes/fees that AF quotes, as DL will do it differently.

Once you've found an itinerary, go to DL.dumb and search by schedule for your award ticket, selecting exactly the flights you found classic awards for with AF. Should price out at 100K per person (for business...60K per person for coach).