For females, I am currently using the GIJOE movie figures of Scarlett and the Baroness. Both figures are well made and the plastics are much stroger and more dense than that of the Star Wars and Marvel series figures...especially around the arms and shoulders where I like to dremel down as thin as possible. If you consider the entire figure being resculpted, I need to have a strong structure to hold the FIXIT and allow the skeleton to take the stress of the articulated movement...a softer plastic would give, making the FIXIT surface stressed and easily cracked over time.
For male figures, again the GIJOE movie figures tend to make the best skeletal frames - although the one thing I don'tlike about the GIJOE figures are the lack of ball jointed knees. Not a problem though - I will sometimes remove the JOE legs just above the knee and add ball jointed lower legs from an existing figure - When working with male figures, Evolutions Darth Bane has great legs!! LOL!
Another item I am finding usefull is the hip articulation used on the VOTC Luke and Medical Frigate Luke Skywalker. As you can see with my custom above, I have carfully removed the hip portion of the VOTC Luke and have added it to the skeletal frame. I will soon dremel down the original details before sculpting.
So now you know a bit of what goes into the early stages of the figures I create - it's probably the least fun stage of the custom process...which is why I sometimes take a full day just preping figures...multiple ones, just to have ready and get the dremeling out of the way (and clean up the massive mess if leaves behind).
Now for the fun part - sculpting!! Which is what I'm doing creating yet another Vong soldier seen below. Taken from the pages of Star Wars Invasion - these Vong soldiers guard the waters of Artorias in the midst of vongforming.
More pics will be available soon on my photostream, http://www.flickr.com/photos/sith_fire30/ so check in from time to time for updates :)
I will be sure not to let so much time pass till my next update - Take care till later!