I think you've missed any eastward transatlantic trips for this year. In general, you will find few leaving from New York. The majority leave from the Caribbean. Those leaving from the east coast of the US will have headed for Bermuda and on from there, and would generally have done it before now. This is hurricane season, and even though the odds are small that one would form this early, the tropical waves and depressions coming off the coast of Africa can make this time of year a bit difficult. http://www.marionbermuda.com/index.shtml
For what you want to do, I think that you need to plan a year in advance and line up the boat you'd like to be on. The 2008 Newport, MA to Bermuda race started on June 20 this year. Next year's Marion, MA to Bermuda race will start on June 19, 2009.
You might get in touch with the race committees of these events to see if they could help you find a boat continuing on to Europe, and perhaps you could meet them in Bermuda. Please be completely straightforward about how much gear you will be carrying, because skippers will probably be a bit leery of taking on you and your gear. http://www.bermudarace.com/