Well, there are several CAS slider(s) mods out there that do a terrific job. Some do certain parts of the body while others do all of the parts of the body.
This is the
CAS Slider mod that I use in conjunction with Awesome Mod (from MATY) to make my Sims the way I want them to look. That one is the best I've seen in my opinion.
I don't know of any mod out there that can do poses yet, but keep looking on the Internet for one to use with Sims 3. Treeaq (or Treeag) at MTS has a box that do the locomotions for Sims 3, so it might be worth a look as well as the other Sims 3 offerings she/he has.