[Untersturmfuhrer Draksen]

I don't think that you can choose "Omaha Beach" with an agency.
From the States or Canada, the easiest way would probably be :
1- go to Paris, by plane.
2- by train, go to Normandy (under 200km).

but it depends of what you want to do, to see, and how long you think you will stay in France.

IMO, Omaha Beach is interesting, but only 1 day (may be 2 max) is required for visiting it + the museum + other "Overlord sites" on the coast.

------------------
Untersturmfuhrer J.Draksen,
Virtual Wiking Division