Slipperential is pretty much just as you described. Good idea if using the tekin to save somee stress on the rotor. Not sure if elite do a mount but I am nearly sure rc monster do. Very helpfull advice over there on all conversions and brushless combos. Also the only place to buy a slipperential as its the owner who created them. Hope this helps you.
http://www.rc-monster.com/forum/showthread.php?t=18982