Some of the things you mention sound like common Moodle Myths: http://docs.moodle.org/23/en/Moodle_myths
There are plenty of US universities moving to Moodle. I was at the Mountain Moodle Moot, and there were people from nearby universities there making the move.
You could also look through the list at http://moodle.org/sites/index.php?country=US
This is now a few years old, but well worth a read: http://moodle.org/mod/data/view.php?d=19&rid=2531&filter=1
And here is a group of universities working together on adopting Moodle: http://www.clamp-it.org/about-2/
Also, if you university wants to spend Money, that is, if they are more comfortable with a commercial service, you could suggest they talk to Remote Learner or MoodleRooms.