a #10 sharp maybe easier---(assuming you've been using betweens- the sharps are a little longer) warm & natural is really not meant to be hand quilted (or any batting with scrim- the scrim helps keep them together for the tugging/turning/rolling during machine quilting-
hobbs heirloom or quilters dream is a better choice- but assuming that is too late you will have to experiment with needles- (and thimbles) to find the right combination.
I use sharps or milners normally- i like the longer shaft-
and #12 milners may even be a better choice for you---longer and finer needle- but they will bend sooner doing (heavy sewing) with them. i like the John James milners- but there are lots of different brands to choose from.