Sometimes a quilt is not a quilt because of weight but perhaps your have a super wall hanging in the making! I might suggest that you look at the square-in-a-square block too, although the snowball block might leave more space per individual block. Of course all those patches are going to be different sizes. As for quilting it, one might consider the quilt-as-you-go method. While I am not affiliated with this site
http://www.graspr.com/videos/Quilt-a...other-Method-1 I have used it as an explanation. One day I am going to make a large something with quilt-as-you-go because one could do detailed quilting with small blocks compared to having a large quilt in front and all around the needle.
Good luck and do post your progress.