well i found this list yesterday when i was trying to find a chin width slider.
pretty much, i just google whatever i need and click everything until something looks okay to install.
i search google images too because sometimes that takes me to a site that the normal google search wouldn’t through a picture.
http://modthesims.info/ is another pretty good site for things like that, but just make sure whatever you install is good and won’t make your game crash and lag like mine was doing.
also, if you get too many, you’ll probably need awesomemod (here’s the configuration to download a customized version of awesomemod) or the other one that first link mentions because the game by itself will only show so many sliders.
i didn’t install enough to need either of those yet and i probably won’t need to.
also here’s the butt slider, along with some other sliders included. it says use at your own risk because the creator hasn’t logged in for a while, but it still works. i forgot to mention that you might need to sign up on this site in order to download things from it, but it doesn’t take too long and i have mine just always logged in so i don’t even notice.
i am also assuming you know how to install these into the game, but if you or anyone else doesn’t, i can always help with that too.