I've been doing big stitch quilting with #8 perle cotton for years.
I've also used Sulky 12 wt. threads, old candle wicking threads, Sashiko threads, and #10 crochet thread, often in contrasting color to show off the stitches.
I prefer John James #3 -5 between needles (I have some nerve issues in my hands and have trouble with feeling a needle with my fingers.)
I quilt with wool batting or Quilter's Dream Cotton Select. My stitches are about 6 inches to the inch (counting top of quilt only).
Love, love, love this method!!
Jan in VA