When I want a higher loft I use double batting . One layer of a Warm and natural( or similiar) , the next a low loft poly . It gives great texture and is much more easily quilted. I switched to this after having some "issues" with stiching in the ditch on high loft.
It also gives the puckers when washed a bit more fluff. Try it on a small sample piece.
For extra soft , try using Minkee for the backing, its really really soft and quite irresistable.