Hobbs poly down and wool are both super easy to hand quilt through. I would also recommend to get a wide back fabric for the backing. That way you only have to deal with seam allowances on the front. Any kind of wide back will do, muslin or print but I would recommend prewashing as this will soften it up, remove factory sizing, preshrink and will alert you if it has excess dye if you get a color or print. No worries about bleed with muslin which is a plus. There are loads of places that carry w/b dirt cheap too, especially muslin. Marshall dry goods is a good one.
https://marshalldrygoods.com/shop/home/108/widths/?
PS want to add I gave that 8 wt some thought and think you are better off with a regular hand quilting thread. An 8 wt would be an absolute bugger to pop the knots through the fabric, even if you did the knot popping from the back. I like a 35 wt thread for hand quilting. Valdani makes a lovely one. YLI is also very nice and just a wee bit lighter at 40 wt.