So Chris, you've decided you would like all the fame and glory that comes with building a route that Auran decides is appropriate for release on one of it's commercial ventures, Eh?
As someone who has done that twice now, I think I can comment.
Make the route about midsize, have it contain only items downloadable from the DLS, obtain written permission from creators for use of items not on the DLS, and have the route made so that it showcases the current innovations Auran is trying to promote at the time. You can begin a dialog with Auran through the helpdesk, but be prepared to wait for awhile. I don't know what the shedule is for release of any more Trainz Routes, and I'm guessing the next Classics will feature routes from other parts of the world than the USA.
Good luck.
Ed