I also tried different polymer clay- I'm personally not a huge fan of those. But it is just a matter of preference. The kneading really bothered me! I wasted so much time just doing that instead of sculpting. Then again, I haven't tried all of them.
I have been looking for something that would dry fast enough so that when touching the already sculpted parts they wouldn't get damaged or lost shape.
I am now working with DAS air drying clay- pure awesomeness! I hear LaDoll is easier and better to work with; apparently when mixed with Premier, nothing can compare in the sculpting doll world!
The artist Hannie Sarris helped to create a ready mix of those two clays: Premix.
I am planning to try that as soon as I can get it delivered.
In the meantime, some photos... :)
(Please ignore the size of the bum, it will be a bit smaller eventually.)