2001 Chrysler Town and Country Transmission issue

I'm fairly sure the tranny is gone, but here's what's going on:

My wife was driving at highway speed yesterday when she heard a big "clunk" which shook the van. The van then lost drive and coasted to a stop. She had absolutely no movement in any gear. The van would go into park. After letting the vehicle sit for a moment, she started had all forward gears, but no reverse. However, you could only go about 5-10 mph before you would lose 1st gear and have no movement in any gear again. I pulled the codes and this is what I found: P0720, 0734, P0732, P0700. They're all transmission related, just wondering if anyone with much more knowledge than me has any imput. Am I looking a a new transmission or could is possibly be a sensor or solenoid of some sort. There is no grinding when in any gear. Any help would be greatly appreciated.