brenda,
i would sure love to see a picture of your quilt. sounds amazing.
i am not the best one to give quilting advice but when you were describing how you want to quilt it i was picturing the process. seems like you might want to check the back fairly often and plan to repin as needed to avoid wrinkles.
others are much more experienced with the quilting part than i. i'm sure you will get some good advice here.