Just an idea...that's what is under discussion so glad to hear it. I think seeding based on the past tourney results is viable.
This rating can be set/verified by using the "Event Qualification" function in track for your separation criteria.
For example for next year we could establish the following:
6U Champ (System Qualification = 1st place at 2014,2013)
6U Placer (System Qualification = 2,3,4,5 place at 2014,2013 )
C-The rest
What do you guys think of that? Could even add another track tourney as a qualifier as well. Salina I've heard mentioned.