Thanks for your reply! I'm looking for something clean hanging rather than close-fitting. I do have a prominent seat and it seems that the problem is getting the taper from the seat to the leg right. There are double darts being used in the back.
As for the company, they ask for either body measurements measurements off a best-fitting set of pants. I went with the latter. Because of my build, I've never had a something that is trully best fitting so I'm still trying to get fit right. The company allows you to send pictures of how a previous order fits and make comments regarding that fit. They then recommends changes to the pattern/alterations to the pattern that they have for you on file. Over the 2 times that I've done this, the managed to fix the "wedgie" issue that I was having. However, the sagginess behind the thighs remains.
It is very difficult to advise at this point with out seeing the pattern, which won't happen.
There is a particular balance between the shape/curve and angle of the CB line and the thigh and the length of the back inseam which isn't quite there yet.
I hope you succeed in getting closer to what you are after.