Hi ladies - I know there was a thread about this previously, but I have a question about spanx. My dress is one shoulder, so I'll either need a one piece shaper that includes a bra or a high waisted shaper with a strapless bra. I've never worn spanx before, but in looking at reviews for body shapers in general, some of the comments are that it rolls down. D you have a shaper that you recommend that stays up? Thanks!