Hi. Lovely quilt. I've made the same pattern without borders and think quilts without borders look wonderful. If you want a bigger quilt, just add more blocks.
As to purchasing material for scrap quilts, you could buy fat quarters, fat eighths, or, regular quarter or eighth yards in what ever fabric you like.
I've purchased as much as twenty eighth yards at a time off bolts in order to have different fabrics for colorful scrap quilts. It works well to obtain a variety of patterns and colors.