Dont know if this may help
http://www.kadair.org.ukFollow the link to
Oceanic for NAT selectors and so on.
Ive not flown Trans Atlantic yet but the CEO of this Airline is probably one of the Virtual Authorities on it.
I really can't recommend FSNavigator enough though for route planning, has all the Sids and Stars, all the airways with directional and upper/lower info. Has all the navigational beacons with quick reference all airprts, if you play multiplayer you can see other aircraft.
I try and use it for planning and reference without using it to see where I am, but if you want to you can use it as a Flight Management System and it will fly the aircraft for you. I would have thought it was great for Trans-Atlantics where you can switch the FMS on whilst leaving the flight deck for a meal etc.