This is the deck I developed for, and eventually managed to succeed at beating the Defense of the Havens quest, the last quest of the Grey Havens deluxe expansion. You can hop on over to my quest log to see how the eventual winning battle went, but i'll note here several of the nuances of this deck.
Cirdan quests, Elrond quests or defends, (ideally with Light of Valinor for both), and Gimli kills things. Be sure to take some damage on Gimli early to get his attack up.
Your ideal "engine" includes Light of Valinor, and Vilya on Elrond, with Imladris Stargazer in play. This sets you up to plan for what card you are going to keep and discard with Cirdan on the next turn. You also set your deck (deeper down) to put into play an ally of your choice with Elrond.
Further cards that synergize with this engine are Expert Treasure-hunter, on first Cirdan, but then also Elrond as you can "hit" 100% of the time with your Stargazer in play. You can also "float" your high-cost allies at the top of your deck while you wait to find Vilya, or if you see an Elf-stone get them into your hand. While of course the awesome power of Vilya takes this deck to its greatest heights I wouldn't call it a "Vilya" deck because it can operate without it.
Snowbourn Scout might seen a little bit odd, but Elrond can play him, and it can be helpful to have another few chump blockers when the time comes. Mirkwood Runner was a bit of a quest-specific include since he can two-turn Na'asiyah. While the deck starts with higher threat than most, Elrond's Counsel + Gandalf (in a pinch) should be able to keep you from a threat-loss.