I just finished a string quilt and used Pellon 830 as the foundation. Was great to work with and my long arm pro who quilted it said it was a breeze to quilt through. I bought it by the yard, I think it was about 40" wide, and on sale was just a little over $1.00 per yard. I cut it into 12" squares for my quilt. I will post a photo of it tomorrow. Sorry I don't have any experience with the 2 products you listed though.