For future reference (since you've decided otherwise this time):
I do big stitch quilting with #10 crochet thread, BUT I use all cotton quilting weight fabrics for front and back and I use wool batting for ease of stitcching.
I hand baste for several reasons -- I don't have a well ventilated space large enough to use the spray baste; the 'sandwich' stays together better (for me) over the long period it takes me to handquilt, move, the quilt, re-hoop, fold it out of sight, drag to guild and bees for working on; I prefer the feel of the finished, washed quilt's weight and softness with wool batting. I use a cotton batt for quilts that I machine quilt.
Jan in VA