I just finished doing my first big stitch quilting and found that the process is much more "organic" than traditional quilting. Keeping the stitches even and the same on top and bottom is not necessary. I enjoyed the process and will be doing it again.
After I was 90% through the quilting, I discovered a Clover Gold Eye Millner needle#5 was perfect. It was very sharp and easy to work with. I was using Aurifil 12 wt, so the small eye worked fine.
Have fun - it's a beautiful quilt and you will be so much happier with it when you have completed it.