I'm a size 6/8 but my thighs are quite large so I'm always having problems with stockings digging in. Like Sam said, the ones without bands are great. I have these
fishnets and they would easily stretch to fit someone with thighs several inches wider than mine.
Eden also carries a good selection of plus sized stockings
link
I'm planning on ordering a few pairs and seeing how they work for me. So I don't have any specific suggestions on which ones are good yet.