Quite a few of my quilts end up tied just to get them done, but ALSO because family members want fluffy quilts (they are warmer). I personally use wool yarn to tie because the yarn felts and the ties don't ever come out then. However, lots of people use poly yarn - spend some time learning the special knot or the knots will come out.
As for batting, it's hard to find truly fluffy batting. A good bet is to get the thick poly-on-a-roll at a sewing store. It takes a long time for this to lose its loft,but it is a bit stiff. I really liked Joann's Soft and Crafty high loft when it first came out - fluffy, fluffy, fluffy. It was easily 3/4 inch of loft. Doesn't even reach the 1/2 inch now listed on the package. However, they have since cheapened it and you need to packages laid on top of each other to get a similar loft.