Your quilt is lovely. I would probably go with 'regular' hand quilting (vs big stitch) but that is generally my preference. But you could easily do 'big stitch'. It's truly a personal preference.
And I normally use Warm & Natural batting. I've quilted it for years with no issues. That said, I just finished up quilting a quilt for a friend of mine who uses Quilter's Dream 100% cotton batting. Definitely nicer to quilt through and has a better 'drape' right from the start. When I finish up my bolt of W&N that is the batting I to which I will switch.