The CM T-800 is the best representation of the Endoskeleton on the market.
I say this an an owner of the Sideshow lifesize version.
1. Stan Winston involved in its production.
2. Most accurate Endoskeleton on the market because of #1
3. Only Endoskeleton with fully sculpted spinal cord
4. Excellent base
Only niggle I have with it is that I wish it had slightly better light up effects. The 1:2 scale Sideshow version has the blue lights off the base which is very nice. Also, would have been great to have the "slow dimmer" red eyes fade like the Sideshow versions.
If you're lucky, you can get one between 2000 and 2500 dollars.
Also note there are subtle differences between each one with regard to paint oil application, "shinyness" of chrome, how far the head is turned, etc. I've personally owned 3 of them so can attest to this.