Scoop - use flightconnections.com - All flights worldwide on a map to find out who operates between FCO-AMS. Quick look shows EasyJet, Vueling, KLM and Alitalia. Not at Delta yet (8/8 class) so not familiar with ZED options but I'm sure you guys have KLM which we've used in the past.

Might ensure you are on a high speed train to make it, that is a good journey that far north. Or an overnight train as well but you'll likely have to make one or two train changes.