That’s a fantastic idea!
CityDesk had a post last week about trying to find a good date where the setting sun would exactly line up with some of DC’s main streets, creating a cool sight with an orange glow coming all the way down, say, K street. Channeling my inner Eddie Izzard, that’s a fantastic idea!
If you’d want to emulate the visual impact of Manhattan, I think K street is the best bet. Not only does it have buildings on both sides and a nice urban canyon effect, the area immediately to the west of the K Street corridor is the Potomac River just as it bends to the west.
I don’t think New York Avenue would have the same effect looking back towards the White House, as there are a fair number of (relatively) tall buildings that terminate that vista.
Despite the lack of an urban canyon like New York, I think simply lining up a shot down the long axis of the Mall would be cool. Or, looking down Maryland Ave NE, with the setting sun backlighting the Capitol dome. You could pull this off on East Capitol, too.
Or, you could go for the sunrise angle as well, and use shots towards the east.