I was actually looking for something that makes sense for their presence in that city - going through several other books I figured my second best guess would be Transilvania chronicles but during my chat with the players we decided to settle in CBN. I will probably avoid the more powerful cainites in the early games, stick to simple intrigues on fledgling level. Not ready to roleplay Micheal and likes at all ;-) Agents ( willing or not ) of the latin vampires sounds really good, especially since one of the pc is a Lasombra. I will let them decide during the game if they want to preserve or destroy the dream ( or leave all together ).
We managed to adjust their stories and backgrounds to fit in the new ( old ) date, it seems the fixed date in DA20 has no real consequence on the game contrary to my belief and worry.
I guess it's time to learn some history, ready the book and see where it goes ;-) I appreciate all the input from everyone - cheers.