I have hand quilted many quilts .. and have used different sizes depending on the quilt. I think the size I go to most often is the 20" or maybe its 24".
I would second RST's suggestion about waxing your thread. I have used thread magic (little blue box) and it helps dramatically.
I have never used a hoop on a stand. I hoop the quilt up and sit on the couch watchin TV. I did find some needles that were bent into an almost U shap and some quilts those helped to get the needle through the layers.