For everything from the knee up, this one would be my suggestion:

http://www.spanx.com/product/index....rentPage=family

It goes down a little past the knee, but on me that prevents the telltale bulge on my thigh where the shaper ends.

I can't stand when a shaper rolls down on my torso, so I pull it up REALLY high and then put my bra on over it. That tends to keep it in place.

About the bathroom issue...forgive the TMI...but with the Spanx double-gusset crotch it's not difficult.

I find that most shapers are comfortable for about 8 hours or so, but start to get irritating after that.

Hope this helps!